Recommended sales price: 28.50 €
Trademarks Heidelberg, the Heidelberg Logo, Jetbase, Prinect, SignaStation and Stitchmaster are registered trademarks of Heidelberger Druckmaschinen AG in the U.S. and other countries. AutoRegister, AxisControl, Compucut, Compufold, Compustitch, CP2000 Center, DataControl, Delta Technology, ImageControl, Internet Portal, MetaDimension, MetaShooter, Omnicon, Prepress Interface, Prinance, Prinect Printready System, Speedmaster, Sunday, Supercolor and Supertrap are trademarks of Heidelberger Druckmaschinen AG in the U.S. and other countries. Apple, LaserWriter, Mac and Macintosh are registered trademarks of Apple Computer Incorporated. Adobe, the Clearly Adobe Imaging Logo, Acrobat, Acrobat Distiller, Acrobat Reader, Adobe Extreme, Illustrator, InDesign, PageMaker, Photoshop and PostScript are registered trademarks of Adobe Systems Incorporated. AdobePS is a trademark of Adobe Systems Incorporated. All other trademarks are property of their respective owners. Subject to technical modifications and other changes.
Expert Guide 11 • 2002
PDF-Workflow 00.993.6105/01 en
Publishing Information Printed in: 11/02 Author: Thomas Müller Photographs: Heidelberger Druckmaschinen AG Platemaking: CtP Printing: Speedmaster Cover: etabind (patented) Fonts: Heidelberg Gothic, Heidelberg Antiqua Printed in Germany Copyright © Heidelberger Druckmaschinen AG, 2002
PDF-Workflow
Heidelberger Druckmaschinen AG Kurfuersten-Anlage 52 – 60 69115 Heidelberg Germany Phone +49-62 21-92 00 Fax +49-62 21-92 69 99 www.heidelberg.com
Heidelberger Druckmaschinen AG
Contents About the Author Editorial Why PDF? – Brief Information Basics Trends in Prepress Out of the Office and into the Prepress Generating PDF PDF Documents Can Be Used Anywhere Industry Standard PDF Output PostScript and PDF – the Differences … … and the Things They Have in Common Job Tickets in PDF Automating Output PDF + JDF = Standards for Automation and Transparency Corrections Remote Proofing Other Areas of Use for PDF Summary Creation Why PDF? Workflow Practical Tip: Generating a PDF Document Correct Layout Files PDF Writer or Distiller? Acrobat Distiller PPD Mac Printer Drivers
2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28
Windows Printer Drivers PostScript Resolution QuarkXPress 4 /Adobe InDesign Adobe PageMaker Microsoft Word Using OPI Images Acrobat Distiller Job Options General Compression Downsampling Fonts Font Substitution Font Locations Color Advanced Watched Folders Golden Rules
29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46
Production The History of PDF Generating PDF Documents Correctly Distiller Settings Checking PDF Documents Automatic Document Checking Converting PDF Documents Editing Text Editing Graphics and Images Document Security Color Separation Exporting PDF Documents
47 48 49 50 51 52 53 54 55 56 57 58
Microsoft Office Distiller as a Control Instance OPI Workflow with PDF Documents Impositioning Trimming Print Control Elements Screen Parameters Duplex Image Data Traps DCS Workflow PDF Support for Application Programs Pre-Separated PDF Documents Automating Output with PDF and JDF Recommended Tools
59 60 61 62 63 64 65 66 67 68 69 70 71 73
Management 75 Summary 76 Heidelberg Products for a Smooth 83 PDF Workflow in the Print Industry – Based on PDF and JDF The Approved PDF-X Standard 86 Adobe Acrobat Version 5.0 – Prospects 87
2 PDF Workflow About the Author
About the Author Thomas Müller, a Dusseldorf-based author, advisor and communications expert, began his professional career almost 25 years ago in the prepress sector. He experienced technological change first-hand – from photo setting, reprographics and desktop publishing to electronic image editing and networked publication systems. He founded his company in 1985 in order to concentrate exclusively on the digital creation of computer graphics, presentation and print originals – even before the term ‘DTP’ had been invented and the first Macintosh® could display color. For more than 15 years, he has been nurturing close contacts with manufacturers and developers – particularly with Aldus, Adobe and Heidelberger Druckmaschinen AG (Heidelberg®). As a freelance consultant, Thomas Müller specialized in 1993 on ‘medianeutral publishing’. Since then, his efforts have been closely linked with technologies such as the Internet and PDF. As an expert with many years’ experience, he has clear insight into the various areas of application for the PDF file format – and not just from the perspective of prepress and media production.
Today, he is one of the few Germanspeaking experts who play an active role in introducing PDF to all kinds of fields. He advises companies from the graphic arts industry, but also provides advice to globally active business consultants, multi-national concerns, insurance companies, ministries, administrative bodies and authorities. Back in 1996, he published his book entitled ‘Acrobat & PDF – from paper to digital information’. Instead of issuing updated printed editions of this work, he initiated an online German-language information forum for Adobe Acrobat and PDF in 1999 known as ‘pdfzone.de’ – http://www.pdfzone.de. Thomas Müller delivers lectures and moderates countless events. Readers and listeners appreciate his entertaining way of communicating information. As an expert in communication, he is aware of the importance of one indisputable fact: “Changes in behavior start in the head – if you have the insight to make them.”
Information on Adobe Acrobat and PDF: http://www.pdfzone.de.
Editorial PDF Workflow 3
Editorial Welcome Readers! It’s great that you want to learn about PDF for the prepress stage. PDF and Adobe® Acrobat® have already become well established in the prepress sector. Very often, however, there is a lack of methods and approaches when implementing the ‘PDF workflow’ and what lies behind it. There is now a gradual realization among graphic arts businesses that the only companies to profit from the PDF workflow are those that train their staff and their customers to create and supply PDF documents correctly. Systems manufacturers and expert advisers will help you towards this realization. It is with this in mind that Heidelberger Druckmaschinen AG (Heidelberg) was one of the world’s first companies to concentrate entirely on PDF in the prepress sector and develop a PDF-based workflow. Expert tools require expert advice – so call the experts. Profit from their products and their expertise. Heidelberg and Adobe have built up a very close relationship since the beginnings of PostScript®. Heidelberg uses proven Adobe technology in many of its products, and natu-
rally plays a key role in its development. This brochure is intended as a tool to help you along the route towards an efficient PDF workflow. Give it to your customers, suppliers, employees and anyone else who works with you! This brochure can bring you profit as you go about your daily business. It can also serve as a means of exchanging information with colleagues – either at one of the numerous events or via the Internet. Seize these opportunities! I wish you every success as you read this brochure and as you begin to implement the information it contains.
Thomas Müller pdfzone.de Dusseldorf
4 PDF Workflow Why PDF? – Brief Information
Why PDF? – Brief Information PostScript was a revolutionary invention that kicked off a revolution all of its own. Its goal was to provide a uniform standard for controlling output devices – and one that also satisfies the needs of the graphic arts sector. The effects of PostScript are clearly visible, since the graphic arts industry has changed fundamentally since Adobe first invented PostScript more than 15 years ago. PostScript was dynamic and flexible, and tailored to the needs of print or imaging. The transfer of document data in PostScript was however a shot in the dark, since the results only became visible once imaged films landed in the developer’s out-basket. All attempts to display PostScript on screen failed due to a lack of system resources. It was also extremely expensive and occasionally totally impossible to test and analyze job data in PostScript before production got underway.
Adobe itself recognized that PostScript was not particularly ideal for exchanging documents. From this recognition came the ‘Portable Document Format’, PDF. At first, PDF was envisaged as electronic paper for the office environment. But the graphic arts industry soon realized that PDF could offer a solution to the industry’s PostScript problems. As a result, Adobe concentrated its research efforts more and more on the needs of graphic arts users. With PDF 1.3 (introduced in 1999), it was possible to transfer print jobs – including spot color vignettes and color definitions in HiFi color without losses – in PDF file format. The PDF file format was optimized so that the information required for print production was not lost, but the documents could still remain impressively small. PDF developed to become the standard that is today accepted throughout the industry. Several hundred million users have already downloaded the free Adobe Acrobat Reader® from Adobe’s web servers. Users do not need any other tools to be able to load, read and print PDF documents.
The graphic arts industry loves PDF, since it enables job data to flow more smoothly – right through to the printing and imaging system. PDF became the baseline data format for all state-of-theart workflow systems used in print production. The logical separation of job data (PDF) and processing information ( Job Tickets) afforded modern production facilities the degree of flexibility they needed to operate efficiently.
Basics
Creation
Production
Management
6 PDF Workflow Basics • Trends in Prepress
Trends in Prepress Since the start of the DTP revolution, the prepress sector has changed enormously – through the invention of PostScript and the application programs that went with it. Networks of distributed workstations in offices, advertising agencies, prepress businesses or print shops have replaced once specialist areas such as photo setting or electronic image processing. The trend towards completely digital prepress is unstoppable. Digital printing systems and large-format imagesetters for films or printing plates require endto-end digitization if they are to be used cost-effectively. Digital sheet assembly replaces the work done at the light table, while classical print proofing methods are giving way to ‘remote proofing’ systems at the customer’s. A universal exchange format for documents is essential for a seamless digital workflow. Adobe developed the PDF file format, which has now been accepted as the standard format for document exchange. In digital prepress, Adobe PDF is becoming a popular alternative to exchanging films or other print documents.
Adobe PDF replaces films and other print documents as a transport medium.
Digital printing and Computer-to-Plate or Computerto-Press require digital print forms. Redigitization of analog print originals is an expensive workaround in the long term.
Basics • Out of the Office and into the Prepress PDF Workflow 7
Out of the Office and into the Prepress Adobe developed the PDF file format (Portable Document Format) in order to give life to the vision of a paperless office. Digital documents should be as easy to exchange as paper – no matter what operating systems are involved. As a result, the first version of PDF was ideal for the screen and laser printer, but not for the needs of the print industry. Adobe continued to develop PDF sympathetic to the needs of the graphic arts industry. Gradually, electronic paper for the office gave rise to electronic film for the print industry. PostScript often caused problems due to its tremendous flexibility. PDF helped to eliminate these difficulties. PDF Version 1.3 and the associated Adobe Acrobat 4 package brought the print industry up to speed in 1999. Acrobat 5 and PDF 1.4 cannot improve on this situation much, apart from offering creative professionals the ability to transport transparent objects in PDF documents, for example.
PDF has changed from being the industry standard to the global standard.
But the PDF file format contains further features that make it more interesting as an archive medium. Content from PDF documents can be used and reused far more widely and often. And PDF documents can be made up as an electronic publication on the display device’s screen. PDF has changed from being an industry standard to a global standard. The automated workflow systems of the graphic arts industry’s major manufacturers – including Heidelberg’s open and modular Prinect Printready System™ and MetaDimension™ workflows – are all based on the PDF file format.
PDF development took it from being used as electronic paper for the office to becoming electronic film for the print industry.
8 PDF Workflow Basics • Generating PDF
Generating PDF PDF documents can be generated in a host of different ways. Users of Adobe Acrobat have two ways of doing it: • Acrobat PDF Writer is a printer driver that can be installed where necessary under Windows or Mac OS. • Adobe Acrobat Distiller® is a PostScript interpreter that generates PDF documents. It can also be used under Windows and Mac OS like a printer. PDF Writer has some limitations. Color data, for example, is only transferred to PDF documents in the RGB color model. PDF Writer cannot process EPS documents, and image resolutions can only be reduced with a default, programmed value. Anyone wanting to generate PDF documents as a basis for a print job would be best served by Acrobat Distiller. The use of Acrobat Distiller is no different from other PostScript output devices. Instead of a film or a printed sheet, Acrobat Distiller outputs a PDF document.
Using supplied default settings, the user can choose the area of application for which he requires his PDF document. Experienced users can also configure Distiller in great detail. These configurations can be stored as ‘Job Options’ and can be called up at a click of the mouse [Creation ‘Job Options’].
Acrobat PDF Writer is a printer driver better suited for use in office than prepress situations.
PDF documents can be generated in many different ways. Adobe Acrobat Distiller generates PDF documents that can also be imaged or printed out.
Local Data
PDF Export
PDF Writer
Internet
Acrobat Distiller
PDF File
Web Capture
Paper Copy
Capture Plug-in
Acrobat Capture
Basics • PDF Documents Can Be Used Anywhere PDF Workflow 9
PDF Documents Can Be Used Anywhere PDF documents can be used anywhere – regardless of the operating system or applications involved. Adobe’s Acrobat Reader software is available free of charge on the Internet for the Mac® OS, Windows and Unix operating systems. This viewer program can be used to open and print PDF documents. Correctly generated PDF documents contain all the components they need to allow them to be displayed, such as font and image data. The PDF generator must make the necessary settings in advance. Otherwise, for example, character sets may be missing which Adobe Acrobat or Reader then has to simulate on the screen [Creation ‘Font Substitution’]. The individual pages of a PDF document can be edited independently of each other. A PDF document can, for example, be divided into individual pages for the sheet assembly stage [Production ‘Impositioning’]. PDF documents can also be corrected at the last minute – for example, if a typo needs to be removed right at the last minute before the job is imaged [Production ‘Editing Text’]. Color information can also be changed or converted with the help of appropriate tools. Every object contained in the PDF document
can be extracted or changed at a later point [Production ‘Editing Graphics and Images’]. One key aspect is the reliability with which PDF documents can be output. The complex page description language PostScript continually presented prepress users with almost insurmountable problems. Barely anyone understood the cryptic error messages on PostScript print jobs, and the source of the error was virtually impossible to localize. With PDF, these situations are a thing of the past. Thanks to the use of PDF, the output speed can also be increased. PDF documents are output significantly faster than the PostScript source from which they were generated. Acrobat Distiller does away with all unnecessary and duplicated components. Thanks to the use of various compression methods, far less space is required for storing PDF documents. Depending on the type of image, various methods can be used – e.g. ZIP for contone originals, JPEG for color images and Group 4 fax compression for line data.
PDF documents can be used anywhere. They are complete, but also compact.
PDF documents serve as containers for the resources required for production.
Job Data
Images
Graphics
Fonts
Text
10 PDF Workflow Basics • Industry Standard
Industry Standard
Text
Graphics
Images
Layout
Layout
Layout
PostScript
PostScript
PostScript
Computer-to-Film
EPS
Computer-to-Plate
The transfer of job data can be standardized through the use of the PDF file format – regardless of the program the author is using. The PDF document contains all the data and components required for production. The PDF file format is becoming the standard for transferring job data. Prepress employees no longer need to be able to master all kinds of programs on different platforms. Fonts no longer need to be reloaded and removed for each job. Troubleshooting is made much easier, since all job documents support standardized methods. The one requirement is that the customer is able to generate and transfer PDF documents. In most cases, ‘Acrobat Distiller’ is used for this. This procedure can be automated for high-throughput applications using ‘Watched Folders’ [Creation ‘Watched Folders’], where the production facilities can supply the default settings [Production ‘Distiller Settings’]. This makes generating PDF documents easier. In order to create
QuarkXPress PDF-X/3 is the standardized file format for transferring job data in the graphic arts industry.
Thanks to its standardization by the ISO, PDF is a reliable exchange medium for job data.
the PDF document, the author needs to invest in the Adobe Acrobat package. Applications such as Adobe InDesign®, Illustrator® and PageMaker® can generate PDF directly. All well-known applications for creating print originals, graphics and image data can generate PDF documents. In Standard15930, the International Standardization Organization (ISO) specifies which conditions job data in the PDF file format must satisfy.
Basics • PDF Output PDF Workflow 11
PDF Output
Composite PDF
Acrobat
Acrobat
Composite EPS
Layout
Hot Folder
Composite PS
PS L1-RIP
PS 3-RIP
PS L2-RIP
Output
Output
Output
Separated PS
PDF documents can be output or imaged in many different ways. They can be processed directly in a ‘PDF-compatible’ RIP (Raster Image Processor) with PostScript 3. The workflow steps needed for output is then completed in the RIP – including color transformation, color separation, screening and even trapping where this is supported. PDF documents need to be changed back to PostScript if PDF cannot be edited directly in the RIP. In this situation, the PDF documents are printed out with a print command from Adobe Acrobat – and are color-separated if the appropriate plug-in is available [Production ‘Color Separation’]. There are two options available for adopting and placing ads in PDF file format, depending on the capabilities of the layout program being used: • Direct placing of PDF documents. Modern layout programs such as Adobe InDesign support this method, making conversion unnecessary [Production ‘PDF Support for Application Programs’].
Various output methods can be used, depending on the version of the PostScript RIP.
PDF documents can be output on any PostScript output device.
• Conversion into EPS file format (Encapsulated PostScript). This conversion is most often required for older layout programs. Adobe Acrobat 5 enables PDF documents to be saved in EPS file format. Users can select the EPS version and thus save it with backwards-compatibility to EPS Version 1. This enables the color separation to be performed in the layout program. This method can also be used for entire pages [Production ‘Converting PDF Documents’ and ‘Exporting PDF Documents’].
12 PDF Workflow Basics • PostScript and PDF – the Differences …
PostScript and PDF – the Differences … PDF is based on the same display model as the programming language PostScript, which was developed at the start of the 1980s. This page description language offered the first ever facility to output graphics, images and text on different print or imaging systems using the same method. Adobe’s inventors had designed PostScript to be highly flexible. This tremendous flexibility brought problems with it, as most software manufacturers used PostScript in their own particular way. The same content could be defined in PostScript in numerous different ways. Problems were experienced time and again with interpretation – it all depended on the origin of the PostScript. A page description language of this complexity isn’t suitable for on-screen display, since the necessary system resources would be too large for fast on-screen output. As a result, PostScript errors were almost always only discovered on the output device – by which time it was too late.
PDF, unlike PostScript, is a file format and not a programming language. A PDF document is organized internally like a database. The necessary information is called up instead of being calculated. This avoids interpretation problems and, what’s more, the output speed is faster. The biggest difference is the type of output processing supported. PostScript print jobs have to be processed from start to finish – even if errors occur halfway through a job. The stack-oriented
language does not allow the user to enter and leave as he wishes. This is also the reason why error messages are often misleading. When an error occurs, the confusion is great and, in most cases, a lot of time is spent trying to discover the actual cause. Users can use a PDF document just like the output system’s RIP. If one page is to be edited, the relevant objects are selected as in an address database.
PDF is more a database file format than a programming language like PostScript.
Three steps to output: Interpretation, interim storage and screening.
e.g. with MetaDimension from Heidelberg
PostScript File
Interpretation, Rendering, Screening
Separation
Imaging
Basics •… and the Things They Have in Common PDF Workflow 13
… and the Things They Have in Common PostScript and PDF use the same method to display data and output it on paper or the screen. The result remains identical, regardless of whether PostScript or PDF is used. The PDF file format is the result of an invisible interim step in the PostScript RIP: The display list is where the objects are stored temporarily until the entire job has been interpreted. A decision must be made prior to output as regards which object is to cover another and where something is to be trapped. Only after this check has been performed can a page be screened for the output device.
Acrobat Distiller is a PostScript interpreter that stores its display list as a PDF document. The screening stage is not required in Distiller. As a result, less memory and processor power are required than with a RIP, which has to screen the data for an output device. The operating system screens the objects stored in the PDF document for nonPostScript output devices. For devices with PostScript, the RIP does the screening. PDF reassigns the ‘interpreting’ and ‘screening’ stages. This accelerates output. The RIP is supplied with a complete display list in the right order.
The time-consuming interpretation process takes places in the Distiller. Errors are detected significantly earlier than previously on PostScript output devices.
PDF is a stored display list that was previously generated in the background in PostScript devices.
PostScript File
Interpretation
Display List
Rendering
Contone
Screening
Screen Dots
Imaging
PostScript File
Interpretation
PDF File
Rendering
Contone
Screening
Screen Dots
Imaging
14 PDF Workflow Basics • Job Tickets in PDF
Job Tickets in PDF
A JobTicket is either embedded in the PDF document or enclosed as an autonomous file.
A PDF document should be the original form of a template for media production – in other words, a digital master. This master must be media- and deviceneutral. As a result, PDF documents do not contain any device-specific information. Control commands – such as those for selecting a paper bay or a film magazine – are not provided for in PDF. All commands and information that are not required for the actual representation must be transported separately. With this in mind, Adobe has developed a file format for transporting administrative data – the Portable Job Ticket Format (PJTF). This file format has the same strict hierarchical structure as PDF. The separation of page content and processing information offers greater flexibility in production. The master remains the same, even if printing process changes or a different printing press is used. Only the processing information is modified. This means, for example, that an offset job with spot colors can be output quickly on a digital press with four inking units using the same master. In this case, only the job ticket is modified.
In 1999, four of the best-known manufacturers in the graphic arts industry – Adobe, Agfa, Heidelberg and MAN Roland – devised a universal standard. The ‘Job Definition Format’ (JDF) became the general standard for electronic Job Tickets. Since 2000, the CIP4 Consortium has also supported this concept and is now in charge of the administration side of the concept’s further development. Its new name is the ‘CIP4 Organization’ (see http:// www.cip4.org). Job Tickets contain processing information such as: • Trapping parameters. • Output parameters for filmsetters, platesetters or presses such as screen ruling and screen type. • Impositioning parameters. • Material preselection for imaging or print. • CIP4 parameters for ink zone presettings on the press.
Flexibility thanks to the separation of graphical data from processing information: PDF and JDF.
• Finishing parameters for folding, cutting and gluing. • Delivery data such as job run size and delivery address. • Planning data, e.g. deadlines. • Administrative data such as operator or job number. • Job history for post-costing.
Basics • Automating Output PDF Workflow 15
Automating Output The tasks in the prepress stage are highly diverse and complex. It makes more sense to standardize processes rather than image individual pages. Before imaging or print production, there are a number of typical process stages to be worked through: • Embedding high-resolution image data (OPI) or optimization (downsampling). • Verification of data for production compatibility (preflight). • Trapping. • Color transformation (color management). • Output of proofs. • Impositioning of forms.
• Output of form proofs. • Imaging or transfer of print data. • Archiving of forms. These recurring processes can be automated. For the last few years, a number of manufacturers have been supplying output workflow systems to cope with this task. The first solutions were closed systems that used proprietary data formats and only worked with PostScript in some cases. All modern workflow solutions are now based on a combination of page data in PDF file format and processing information in the form of Job Tickets. This workflow architecture has been developed by Adobe and is known as
‘Adobe Extreme®’. Extreme forms the basis of all major manufacturers’ PDF workflow systems. One of the pioneers in this field was Heidelberg, with ‘Prinergy’, a concept that was developed in close cooperation with Adobe.
Modern workflow systems are based on PDF and JobTickets.
Workflow systems automate the workflow stages – from incoming single pages to fully impositioned print sheets.
Refining
Page Proof
Imposition
Form Proof
Renderer
Imaging
Archive
16 PDF Workflow Basics • PDF + JDF = Standards for Automation and Transparency
PDF + JDF = Standards for Automation and Transparency
Only PDF and JDF support fully-digitized production on an industrial scale.
Standardized processes, in conjunction with standardized file formats, support a greater degree of automation, increased flexibility and – for the first time ever – transparency throughout the entire process sequence. PDF and JDF (Job Definition Format) are essential for an automated prepress workflow. The content being produced is supplied and stored in PDF file format. The process definition for the creation
of complete products is contained in the ‘Job Tickets’ – including prepress, press and postpress elements. This processing information is stored as a ‘Job Tickets’ in JDF file format, where it can be modified as required. The development of JDF is coordinated and documented by the successor to the CIP3 Consortium (Cooperation for Integration of Prepress, Press and Postpress). The ‘CIP4 (International Coop-
eration for Integration of Process in Prepress, Press and Postpress) Organization’ already boasts more than 100 members – including the major manufacturers of the graphic arts industry (http://www. cip4.org). The broad membership of the CIP4 Organization, coupled with the goal of supporting a common standard, is a good guarantee that the JDF Job Ticket standard will become widely used. On April 10, 2001, Version 1.0 was released. Hardware and software developers have since been able to base their products on this standard. Users will soon be able to buy these first products. Customers can enter job-relevant information – such as job run size, deadline and delivery address – directly into electronic Job Tickets. This information is adopted by the workflow systems. In these workflow systems, the processing parameters are entered into Job Tickets, which can then also be analyzed by suppliers’ systems. Production companies can call up the current status of orders and presses and, thanks to the ability to integrate management information systems (MIS), can also perform accurate postcosting based on the real outlays incurred by the job.
The digital page data also includes digital processing and job information.
Compatibility with the PDF and JDF standards is essential for future activities – not just in the prepress sector, but also in the entire printing chain incorporating the press and finishing stages and the final finished product. Support for these standards safeguards investments. Only this method makes CIM (Computer Integrated Manufacturing) – in other words the entirely digital manufacture of complete print products – possible.
Basics • Corrections PDF Workflow 17
Corrections Documents in PDF file format can be used for more than just transferring job data. PDF can be used as a means of communication between authors, customers and contractors. Graphic designers and layout professionals can transfer their draft as a PDF document to the customer
Version 4 onwards of Acrobat offers correction tools. Version 5 also supports online correction via the Internet.
via e-mail. The transferred PDF documents can then be opened and printed using the Adobe Acrobat Reader software. The full version of Adobe Acrobat enables the recipient to then apply changes to the PDF document, just as used to be done with the transparent
cover sheets of the finished artwork. Adobe Acrobat features tools for highlighting text corrections, marking sections, inserting comments or flagging up instructions. These corrections can be transferred separately from the original document. This means that the entire job data doesn’t have to be re-sent along the data line. Instead, just the instructions are sent. Version 5 of Adobe Acrobat offers even greater convenience. In addition to the ability to send PDF documents via e-mail, users can also make corrections in an Internet browser, even if the PDF document has been opened via the Internet. In this situation, the corrections are stored on central servers on the Internet. Customers and clients can thus correct job data via the Internet without much effort. The Internet protocol ‘WebDAV’ (Web Distributed Authoring and Versioning) is used for transferring the data. Everyone involved with a job can view corrections and comments – including on the Internet at the same time. This accelerates coordination processes. The comments and correction
With PDF, corrections can be exchanged electronically.
instructions are shown to the authors – summarized either by editor, date or page number. He or the owner of the source document can then ultimately integrate the correction instructions in the application program. Terms or passages of text can be searched for specifically both in Acrobat and the source program. With PDF, corrections to job data can also be exchanged.
18 PDF Workflow Basics • Remote Proofing
Remote Proofing In fully digitized prepress and media production, it would be an anachronism to send proofs and print proofs. PDF documents can be exchanged and transferred via data line or e-mail. As a result, documents can be transferred onto paper at the place they are
required. A binding print proof can be produced where it is needed if the requirements have been met in the PDF document. The standardized file format PDF/X-3 plays a key role in this context. The ISO standard defines which additional information needs
to be included in a PDF document if it is to be reproducible. The use of color management systems ensures true-color outputs. The desired target color space is set using ICC profiles. This means that the proof printer is adapted to the color space of
PDF makes remote proofing possible for the first time ever!
the print process. (ICC = International Color Consortium; http://www.color.org). Modern developments on color printers have improved reliability. The ink application is measured and controlled in the proof printing system. This means that deviations between various systems can be avoided or compensated.
Remotely controlled proof prints at the customer’s – PDF documents contain all relevant information.
Basics • Other Areas of Use for PDF PDF Workflow 19
Other Areas of Use for PDF The Adobe PDF file format is far more than just a means of transferring documents for print production. The raft of features ranges from the archiving of any type or number of documents to digital publications with multimedia components. PDF enables digital publications to be created from printed ones. Very often, PDF is the only way of presenting printed products on the Internet – without any losses in terms of quality or graphical identity. Thanks to Acrobat Distiller’s variable settings, one document can be produced for the prepress stage and another for the Internet – all from the same PostScript print job. This process can be automated [Creation ‘Watched Folders’]. Users expect interactivity and added value from digital publications – or at least links that lead to their desired destination. In state-of-the-art application programs, these interactions can be integrated during the design phase and adopted into the resulting PDF documents. Adobe Acrobat is used where interactivity is lacking in the designer’s application program. Adobe Acrobat enables interactive functions – such
PDF documents can be used for all kinds of applications. Anyone designing and producing documents for printing can quickly create an electronic version with PDF. The PDF files can be protected with restricted user rights and passwords. Areas of application: • CD-ROM containing a year’s worth of newspapers, magazines or other periodicals as a reference volume with full-text search facility. • Digital sales catalogs with shopping basket system. • Advertising material and publications such as annual reports and product documentation. • Interactive presentations with video and audio components. • Checklists and documentation for business processes, e.g. ISO 9000 manual and forms. • Form applications. • The range of solutions that can be achieved with PDF is tremendous – users looking for innovative solutions will be pleasantly surprised. Printed documents can be used to create interactive publications very quickly. PDF documents can be used anywhere – in the prepress sector and in new media.
as bookmarks, links, article flow, form fields and buttons – to be added to existing PDF documents. Version 5 onwards of Adobe Acrobat enables PDF documents to be adapted to the monitor’s available display area. This also means that they can be displayed on mobile equipment such as PDAs (Personal Digital Assistants).
PDF documents can be published onto CD-ROM and distributed with the free Reader. The ‘Acrobat Catalog’ module enables full-text databases to be created – for fast searches beyond the confines of single documents.
PDF is the universal data format for print and new media.
20 PDF Workflow Basics • Summary
Summary The PDF file format is changing the face of the graphic arts industry even more markedly than PostScript. But PDF’s influence isn’t just confined to the graphic arts industry. PDF can be used anywhere where communication is required – either in office situations or for coordination beyond system boundaries. PDF documents can be exchanged, edited, printed and archived. With PDF and the advanced encryption technologies devised by Adobe, publishing houses are just one step away from the electronic books market. The advantage of this is that processes do not need to be reorganized. New links to alternative products are inserted just before imaging. The result is an electronic book that cannot be copied – in other words, a PDF e-book. PDF facilitates communication, the flow of data and archiving processes for businesses involved in the fields of prepress and media production. PDF can also open up new areas of business. The bandwidth varies from digital film to multimedia masters for production scenarios. PDF has become an indispensable vehicle for job data in the prepress
sector. In conjunction with electronic Job Tickets in JDF, PDF forms the basis for the digital job flow. Version 5 of Adobe Acrobat enables even less-experienced customers and company departments to generate PDF documents for print production. The office desk becomes an author’s workstation – thanks to PDF. This opens up new profit and sales opportunities that could previously only be tapped into through tremendous effort. Many will remember the amount of time and effort it took to image a document from a text editing program or Windows computers. Multiple printouts, faxes, copies and so on are something that the user no longer has to worry about, thus greatly boosting efficiency.
• PDF is changing prepress faster than its predecessor, PostScript. • PDF’s future and areas of application stretch far beyond the confines of the graphic arts industry.
PDF is a comprehensive technology, but it is no panacea for disorganized communication or production workflows.
Basics
Creation
Production
Management
22 PDF Workflow Creation • Why PDF?
Why PDF? Up until a few years ago, print originals and job data were supplied in the file format of the application program. Service providers not only had to install all the necessary programs, but also had to know how to use them. For Word and Corel Draw jobs, a Windows PC was also needed alongside the existing Macintosh computers. Support for different programs was a complicated and costly enterprise. Update cycles had to be maintained for all these programs. Fonts also had to be installed and image data transferred for editing the documents. The only alternative was to transfer PostScript files. These, however, were extremely large. They often contained device-specific commands that could hamper the output process. The Adobe PDF file format now offers an ideal alternative to the situation outlined above. Since PDF Version1.3 (Acrobat 4), documents contain all the information and resources they need for the print production stage.
Every Adobe Acrobat user can generate PDF documents with Acrobat Distiller, and these can be transferred to the prepress stage. Acrobat can be used to print, edit, proof, add comments or insert correction instructions to PDF documents. PDF documents can be viewed, inspected and printed out using the free Adobe Acrobat Reader. The user does not have access to modification, correction or comment tools, how-
ever. Acrobat Reader supports Mac OS, Windows, UNIX, Palm OS and Pocket PC, and can be downloaded free of charge from: http://www.adobe.de/ products/acrobat/readstep.html
PDF is a reliable system for transferring documents between systems without having to convert or install resources such as character sets.
PDF documents link the authors of the content with the media producers.
Creation • Workflow PDF Workflow 23
Workflow Documents awaiting production are created as normal in an application program – in a layout, graphics, image or text editing program. The ultimate goal is to create a PDF document that satisfies the requirements of the print production process. There are two ways of achieving this. Export of PDF documents: Stateof-the-art application programs can export PDF documents directly. In this situation, a check must be made to ensure that the included components meet the requirements of the print stage. Care is needed with programs that generate PDF documents of Version 1.3 and earlier. These documents must be checked for compatibility.
A check should also be made to ensure that PDF documents from Version 1.4 onwards are created with transparent objects, and whether these can be processed smoothly in the service provider’s workflow system – right through to output. Generating PDF with Distiller: This method can be standardized and tailored to suit all application programs. It offers the advantage that all PDF documents generated in this way are of the same version and quality. This method is described in detail in the following paragraphs. The generated PDF document is checked for its suitability for print production either visually or using tools.
If the check is satisfactory, the data is transferred to the production facility. The production facility checks the job data the moment it is received. This enables a quick decision as to whether the document can be produced. If not, it will be necessary to look into the matter and to clarify who will carry out any necessary corrections. Subsequently, the page data is processed – fine data is embedded, traps incorporated and color transformations carried out in order to progress the job to the impositioning stage and ultimately to produce the printed sheet.
PDF documents are ideal for exchanging job data – the means of communication between author and producer.
PDF documents contain all necessary resources and can be exchanged without any problems – thus forming the basis for the digital workflow.
Imagesetter Text, Graphics, Image File
Layout File
PDF File
ISDN Transmission
PDF File Platesetter
24 PDF Workflow Creation • Practical Tip: Generating a PDF Document
Practical Tip: Generating a PDF Document Using Acrobat Distiller is the commonest method of generating PDF. This method is the easiest to standardize and automate. 1. Document creation: A document is created in any desired application program. The user works as normal. 2. Printer driver configuration: Prior to output, the necessary printer drivers are installed. Adobe Acrobat installs a PostScript printer driver with the correct PPD (PostScript Printer Description). In the ‘Distiller’ printer settings, the user selects the appropriate values. The service provider can supply these.
3. Document output: Triggering a print command generates a PostScript file. This takes place automatically in the background, or manually if the print output is being stored in a file. 4. Converting PostScript to PDF: With the automatic method using Adobe Acrobat 5, the PostScript file is converted into a PDF document in the background. Using the manual method, the user opens the PostScript file with Acrobat Distiller, thus starting the conversion process. Alternatively, the PostScript file can be dragged to the Distiller program window using the mouse.
5. Document checking: The PDF document is checked for compatibility with the desired production process. For example, are all fonts embedded? Does the image data have the right resolution? 6. Transfer: The checked PDF document is transferred to the contractor (media service provider), who can produce the document based on this verified data. PDF documents are compressed perfectly for data transfer purposes. In integrated workflows, a normalizer, which works with Adobe Libraries, takes on Adobe Distiller’s role as a PDF generator. In terms of function, a normalizer is virtually identical to Acrobat
Create pages in any layout or graphic application.
Configure PostScript printer driver with the ‘Acrobat Distiller’ PPD file.
Generate PostScript file with embedded fonts.
Convert into PDF file using ‘Distiller’.
Checking PDF file in ‘Acrobat’.
Pass on PDF file.
1
2
3
4
5
6
Generating PDF documents is child’s play – provided that the system has been set up correctly.
Distiller – the only difference being that it has a different user interface and often includes additional functions provided by the OEM manufacturer.
PDF documents can be generated from any application program that supports PostScript printer drivers.
Creation • Correct Layout Files PDF Workflow 25
Correct Layout Files A comprehensive knowledge of the application programs used and correct layout files are absolutely essential for generating PDF documents that are ready for production. The PDF file format helps to avoid many errors in the prepress and media production workflows. PDF, however, cannot eliminate errors that result from the incorrect use of the application program. Errors caused by incorrectly created documents are also adopted into PDF documents – e.g. hairlines and unprintable or overlapping objects. Checking tools are also available for layout programs. Errors should be avoided as much as possible before generating PDF documents ready for job transfer. The PDF documents should be as perfect and ready for production as films were previously. Nobody would previously have asked prepress staff to manually correct lines that are too thin.
PDF documents are the transfer format and the interface between creation and production. This does not, however, mean that authors and creative professionals do not have to perform their work with due care and professionalism. In addition, a preflight check should always be carried out before production begins.
Check list for layout programs: • Set the correct paper size. • Set the trimming parameters to the desired size. • If possible, use PostScript Type 1 fonts and avoid TrueType fonts. • Do not select font modifications in the application program (artificial italics or bold). • Use images in the right resolution (scan correctly or reduce the resolution in the image editing program). • Determine sections in the image editing program (unnecessary data ballast). • Do not use hairlines. • Observe minimum and maximum tonal values (e.g. screen tonal values between 5 and 95 %). • Remove superfluous objects – even from outside the page borders. • Delete empty pages.
Correct layout files are the basis for PDF documents that are ready for production.
26 PDF Workflow Creation • PDF Writer or Distiller?
PDF Writer or Distiller? Acrobat PDF Writer was automatically installed with the program up to Version 4 of Adobe Acrobat. This printer driver enabled PDF files to be generated under Mac OS and Windows without the need for extensive system resources. Since Adobe Acrobat 4, it has been possible to address the PostScript interpreter Acrobat Distiller like a printer, so that when Acrobat 5 is installed, PDF Writer is only installed if the user specifically requests it. PDF Writer is a printer driver that generates PDF documents using the operating system’s graphics models. Under Mac OS, it behaves like a QuickDraw printer, and under Windows like a GDI device (GDI = Graphics Device Interface). Neither graphics model supports PostScript commands. PostScript however often forms the operational basis of many application programs in the prepress stage. Choosing PDF Writer as a method of generating PDF documents would mean that valuable options and parameters are lost – especially the contents of placed EPS elements. Only the preview of these would remain.
The graphical application program’s full performance can only be harnessed with PostScript output devices – and Acrobat Distiller is one such device. By using a print file, a PDF document is generated that is ideally coordinated to the prepress and media production stages.
PDF Writer is a tool for application programs in office environments – if no EPS elements are used.
Acrobat Distiller is the first choice where documents for prepress and media production are concerned.
Creation • Acrobat Distiller PPD PDF Workflow 27
Acrobat Distiller-PPD PostScript is a universal page description language for all types of output device. Every PostScript output device has its own description file, the ‘PostScript Printer Description’ (PPD). It contains device-specific information, e.g. the output system’s maximum resolution and the largest possible printing or imaging format. This device-specific information does not form part of a PDF document, which should be device-neutral. For
this reason, the Acrobat Distiller printer also has a PPD. It ensures that Distiller generates PDF documents that are suitable for universal use. Using a different device-specific PPD would have disastrous consequences. Device-specific commands would be embedded into the PDF document. In certain situations, this would make it impossible to print out PDF documents on other PostScript devices. Only the Distiller PPD ensures that the produced
PDF document can be output on all PostScript devices. Control commands and parameters for PostScript output devices only come into play if a PDF document is to be printed or imaged. Then, a printer driver and a PPD that are appropriate for the output device would be selected.
The right PPD file is used for outputting documents with Acrobat Distiller – no other file will do.
When generating PDF documents with Distiller, the Distiller PPD is selected, whereas for output later on, the output device’s PPD is used.
Printer PPD
Layout Program
Printer Driver
Imagesetter PPD
PostScript File
Acrobat Distiller
PDF File
Acrobat
Printer Driver
Output Device
28 PDF Workflow Creation • Mac Printer Drivers
Mac Printer Drivers Adobe Acrobat Distiller expects a PostScript print file from which to generate a PDF document. Following installation, a printer driver known as ‘Distiller’ is available. This can be used for generating the PostScript output file.
PostScript print files for Acrobat Distiller can also be generated using the ‘LaserWriter®’ printer driver from Apple® or ‘AdobePS ™ ’ from Adobe. There are two things to note:
Select the actual virtual printer and with File > Setup > Printer Description choose the Distiller PPD (top). The print menu settings for an output file (bottom).
• Assigning the Distiller PPD: Each PostScript printer driver has its own printer description file (PPD = PostScript Printer Description). The Distiller PPD must be assigned to the printer driver that is to be used for generating PostScript print jobs for Acrobat Distiller. The PPD file is either assigned in the ‘Chooser’ option of the Apple menu or, in the case of the ‘AdobePS’ driver, defined in paper format using the ‘Virtual Printer’ plug-in. • Embedding fonts: The font settings can be made in the print menu and in the settings for the output file. They are essential to embed fonts effortlessly into the PDF document. In Acrobat Distiller, the setting ‘Embed All Fonts’ must be activated. These values are stored in the default settings that can be selected in Distiller. The latest printer drivers can be downloaded from Adobe by visiting the following link: http://www.adobe.com/support/downloads/. The printer drivers can be found listed in the table of downloadable files under ‘Printer Drivers’.
The fonts to be used in the PDF document also form part of the PostScript print file.
Creation • Windows Printer Drivers PDF Workflow 29
Windows Printer Drivers Following installation of the Adobe Acrobat 5 program package, the ‘Acrobat Distiller’ printer becomes available under Windows. This printer driver is used like a normal printer. The printer properties can be called up from the Print dialog box. Here, all the Distiller options can be set before the print command is triggered. The desired default settings are selected from the ‘Adobe PDF Settings’ panel. The ‘Edit Conversion Settings’ button takes you to the Acrobat Distiller settings. You can define your own page formats on the ‘Paper/Quality’ panel of the printer settings if the ‘Advanced’ button is clicked. Here, in ‘Paper/Output’ under ‘Paper Size’, ‘PostScript Custom Page Size’ can be set. This enables print control strips, trimming, register or cutting marks to be output with ease. The latest printer drivers can be downloaded from Adobe by visiting the following link: http://www.adobe.com/ support/downloads/ (Keyword: ‘Printer Drivers’ in the table of downloadable files). When a new printer driver is being installed, an appropriate PPD file must be selected (in this case, the Distiller PPD).
The Adobe PostScript printer driver is used under Windows.
In the Printer Properties dialog box, the Acrobat Distiller settings can be accessed or a default setting selected.
30 PDF Workflow Creation • PostScript Resolution
PostScript Resolution The PostScript resolution has nothing to do with the image resolution. It determines the resolution of the coordinates system.
The resolution of a PDF document is entered in various place, e.g. in the printer driver (top, Windows 2000) or, if the value is missing in the PostScript file, in Distiller (bottom).
The PostScript resolution is specified in dpi. This value has nothing to do with the resolution of image data, but instead refers to the resolution of the coordinates system. The maximum value generally corresponds to the imaging or print resolution of a PostScript device. It is specified in the PPD (PostScript Printer Description), and so also in the Distiller PPD. Here, the maximum value is set at 4000 dpi. A few PostScript commands work independently of the resolution. There are also graphics programs that analyze the PostScript resolution – e.g. for generating vignettes. In order to avoid risking inaccuracies or coarse-resolution elements at the later imaging stage, the PostScript resolution should be set to 2400 dpi. The generated PDF document will adopt the resolution value from the PostScript file.
Creation • QuarkXPress 4 /Adobe InDesign PDF Workflow 31
QuarkXPress 4 The PPD file specified in the QuarkXPress 4 print dialog box takes precedence over the selection in the printer driver. On the ‘Setup’ panel, in the ‘Printer Description’ field, the setting ‘Acrobat Distiller’ is selected. Standard paper formats can be selected for the paper size – or alternatively, the paper width can be defined. QuarkXPress calculates the paper height accordingly. This is how PostScript output is made to a file:
The settings for the print file can be found under the ‘Printer…’ button in the Quark XPress ‘Print’ dialog box.
Adobe InDesign • On the ‘Document’ panel, deactivate the options ‘Separations’ and (if necessary) ‘Registration’ for outputting a color PostScript file (composite). • In the ‘Page Setup’ dialog box, deactivate all PostScript options. • In the Print dialog box, click the ‘Printer…’ button. • Here, select ‘Virtual Printer’ or, alternatively, choose ‘File’ from the selection [Creation ‘Mac Printer Drivers’]. • Click ‘Save’ and enter a file name. The ‘Save Pages as EPS …’ function should not be used to generate a PDF document. This option has the drawback that fonts will not be embedded.
The PPD file is selected in the QuarkXPress Print dialog box – it overwrites any settings in the Print dialog box.
Points to Note in XPress: • Choose correct paper size. • The orientation should always be ‘Portrait’ in order to prevent the page being rotated and the problems associated with this. • Always activate ‘Full Resolution TIFF Output’ in order to prevent changes to the resolution during output. • The output resolution can be selected via the printer-specific options (important for resolutiondependent parameters such as line thicknesses). • The output resolution settings in the XPress Print dialog box have no effect, since these values are overwritten with the value from the PPD file.
Adobe’s most recent layout program Adobe InDesign is based entirely on the Adobe Graphics Manager (AGM), which is also integrated in other Adobe programs such as Acrobat, Photoshop® and Illustrator. This ensures identical use of graphical objects, a fact reflected, for example, in standardized color management between the various Adobe products. PDF files can be placed directly in InDesign and can be depicted in high resolution if required. PDF can be generated without resort to Acrobat Distiller, since the program can export finished layouts directly in PDF format. The newly designed Print dialog box in Adobe InDesign version 2.0 ensures reliable output.
32 PDF Workflow Creation • Adobe PageMaker
Adobe PageMaker Adobe PageMaker also generates PDF documents using Acrobat Distiller. In other words, the PostScript print files are created in the background. Adobe PageMaker can generate PDF in two different ways. With the first method, the PDF document is generated automatically if printing to the ‘Acrobat Distiller’ output device is selected. In the printer dialog box, ‘Distiller’ is selected as the printer in this situation.
The Distiller PPD is assigned in the ‘Print Document’ dialog box (top). If the PostScript file is to be saved, the file name can be entered under ‘Options’ (bottom).
The other option involves PageMaker’s export function, which is intended to simplify the generation of PDF documents. This function enables ‘printer formats’ to be saved and the Distiller conversion options to be stored in them. Using menu item ‘PDF Format’, the desired option can be selected at the press of a button. The export method for generating PDF files offers very little in the way of advantages over the ‘print method’
as far as prepress is concerned. If PDF documents are to be published digitally, however, this method offers a further advantage: Exported PDF documents contain components such as document information, links, article flow, bookmarks and security options. In each case, it is essential to select the correct PPD. PageMaker automatically finds the Distiller PPD during installation if Adobe Acrobat has already been installed.
Adobe PageMaker generates PDF documents using printer drivers and Distiller.
Creation • Microsoft Word PDF Workflow 33
Microsoft Word PDF documents should always be generated in Word using Adobe Acrobat Distiller. PDF Writer can also be used, provided the limitations are taken into account [Creation ‘PDF Writer or Distiller?’]. PDF documents are generated with Distiller just like any other application program: In the printer output dialog box, the ‘Acrobat Distiller’ printer is selected, the desired settings made and a PDF document printed. Word documents are recalculated if the printer type changes. This can cause repagination and thus the creation of new pages. This can be prevented with a setting in the Options: • Under ‘Tools > Options’ on the ‘Compatibility’ panel, the setting ‘Use printer metrics to lay out document’ is activated. Under the Mac OS operating system, this is done under ‘Edit > Preferences > Compatibility’. From Acrobat 4 onwards, Adobe has been shipping a macro package for Microsoft Office applications, and thus for Word. These macros, known as ‘PDFMaker’, enable a PDF document to be generated at the press of a button. The PDFMaker macros in Adobe Acrobat 5 also embed ‘tags’ into the generated PDF documents.
The PDFMaker macros are ideal for interactive PDF documents, but are equally suitable for prepress – provided the right settings have been selected.
These ‘tags’ enrich documents in two ways: • The contents of these PDF documents can be repaginated on the screen to ensure greater transparency. • Contents from these PDF documents can be reused – either in the RTF file format (Rich Text Format) or as HTML (Hyper Text Markup Language). What’s important is that these macros also use Adobe Acrobat Distiller to generate PDF documents. PDF documents created in this way can also be used in prepress, provided the correct settings have been selected in advance for the PDF generation process.
Repagination following a change of printer can be suppressed. The ‘Compatibility’ panel is located under ‘Tools > Options’.
34 PDF Workflow Creation • Using OPI Images
Using OPI Images The OPI method (Open Prepress Interface) was developed at the end of the 1990s by Aldus and Dr.-Ing. Rudolf Hell GmbH, since the performance of desktop computers was insufficient for processing large, real-image data. The OPI method enables coarse image data (preview images) to be used in the layout. Embedded ‘OPI comments’ in the coarse image data provide links to the file containing fine image data. At output, the appropriate fine image data is inserted automatically from an OPI server. In the PDF workflow, there are two possible options with OPI servers. • Coarse images are adopted into the PDF document complete with OPI comments. In this case, the fine image data required for production is stored in the prepress facilities or the print shop. The PDF document remains small and easy to handle. The OPI server inserts the fine image data automatically when this PDF document is output. In this situation, the following setting must be made in Adobe Acrobat Distiller: ‘Settings > Job Options’, then ‘Advanced’ register and ‘Preserve OPI Comments’.
• Fine image data is adopted into the PDF document. In this case, the objective is to generate a production-ready PDF document that contains the fineresolution image data from the outset. To be able to access this fine image data, the author of the PDF document must be able to access the appropriate OPI server. Acrobat Distiller must now receive a PostScript print file containing the image data, which is already in high resolution. This can be incorporated after the image data has been exchanged on the OPI server, whereupon the OPI server stores the full PostScript print data in a folder. With Acrobat Distiller, this data can be converted manually from here into PDF documents. The conversion into PDF is performed automatically if Distiller has been set up with ‘watched folders’. The OPI server’s output folder must then be identical to the input folder of one of Acrobat Distiller’s ‘watched folders’ [Creation ‘Watched Folders’].
The user now prints as usual to an OPI server queue. A few minutes later, the PDF document appears in one of the watched folders’ output folders.
With ‘Helios EtherShare OPI’, the administrator can define queues that generate a PostScript file – with fine image data.
Anyone requiring fine image data in the PDF document must incorporate the PostScript data after the OPI server – a task performed automatically with Adobe Distiller’s ‘watched folders’.
Creation • Acrobat Distiller PDF Workflow 35
Acrobat Distiller Acrobat Distiller behaves like a PostScript output device. The only difference is that it saves a PDF document instead of printing a page or film or imaging a printing plate [Basics ‘PostScript and PDF – the Differences and the Things They Have in Common’]. Distiller works faster than an output device, since it doesn’t have to carry out the laborious task of screening [Basics ‘Automating Output’]. PostScript print files can be converted into PDF documents in various ways with Distiller: • In the ‘Distiller’ program, the PostScript file can be loaded with ‘File > Open’. • The mouse can be used to drag a PDF document into the ‘Distiller’ program window. • Distiller is set up as a printer on which the user can ‘print’ PDF documents. • PostScript files that are to be converted are saved in a folder, which Distiller watches [Creation ‘Watched folders’]. Stored Distiller settings (Job Options) can be loaded at the click of a mouse. The message window displays the PostScript version (3xxx.xxx = PostScript 3).
Distiller settings should only be changed by experienced users.
The conversion settings for Acrobat Distiller are known as ‘Job Options’. They can be saved and loaded at the click of the mouse. Watched folders contain individual ‘Job Options’ [Creation ‘Watched Folders’].
36 PDF Workflow Creation • Job Options
Job Options Adobe Acrobat Distiller offers a raft of configuration options. On the five panels that appear under menu item ‘Settings > Job Options’, there are a large number of options. These are described in the following sections. These settings can be stored in an individual file, which is known as the ‘Job Options’. Production companies are increasingly providing their authors or customers with suitable Distiller settings as a Job Options file. Inexperienced users can then select these at the click of a mouse. Supplied ‘Job Options’ must be stored in the right folder, so that they appear in the Distiller menu (in the ‘Settings’ folder, which appears in the Distiller folder underneath the Adobe Acrobat program folder).
An individual configuration file (Job Options) contains the settings of the five panels that are described in the following sections.
Supplied ‘Job Options’ are stored in the ‘Settings’ folder and can be called up at the click of the mouse.
Creation • General PDF Workflow 37
General On the ‘General’ panel, there are settings that govern the document’s compatibility, resolution and media size. The ‘Compatibility’ file option is important, because it determines the file’s usability in the prepress stage. • Acrobat 3 (PDF 1.2): This option is not suitable for print production that involves duplex image data or spot colors. It should only be selected if backwards compatibility with Acrobat 3 is absolutely essential – for example if the customer still only has Acrobat 3 installed. • Acrobat 4 (PDF 1.3): This setting is suitable for print production involving spot colors, duplex image data and color models with more than four-color channels. • Acrobat 5 (PDF 1.4): Although PDF 1.4 documents can contain transparent objects, these cannot be included in the PostScript print file received by Distiller.
The file option ‘Optimize for Fast Web View’ is intended for cases when PDF documents are being used on the Internet. It accelerates their loading in Internet browsers and can remain switched on.‘Thumbnails’ no longer need to be embedded in PDF documents, since Acrobat Reader can also generate them where necessary. ‘Auto-Rotate Pages’ tells Distiller to automatically rotate pages that are incorrectly orientated. This option can be used both for individual pages and for the entire document. The ‘Binding’ option is intended for displaying double-paged PDF documents on-screen. The default values for resolution and page size are used if the PostScript print file does not contain any of its own values.
From Acrobat 4 and PDF 1.3 onwards, spot colors and duplex image data are also transferred.
Select at least ‘Acrobat 4’ compatibility for print jobs.
38 PDF Workflow Creation • Compression
Compression Image data normally takes up a lot of space, and can also cause PDF documents to grow considerably. As a result, Acrobat Distiller offers various compression methods that enable image data to be stored more compactly.
For color and contone images (grayscales), a loss-free ZIP compression or a JPEG compression method (which is associated with losses, but has the advantage that it can be adjusted) can be selected. With the ‘Automatic’compression setting,
Compression Options Motif
Compression
A B
none none
A B
ZIP 8 ZIP 8
A B
ZIP 4 ZIP 4
A B
JPEG max JPEG max
A B
JPEG high JPEG high
47 207
A B
JPEG medium JPEG medium
35 157
A B
JPEG low JPEG low
31 136
A B
JPEG min JPEG min
26 121
KByte
1,662 1,389 1,037 1,361 181 553 119 370
Distiller selects the compression method according to the image motif. Anyone looking to transfer image data without loss must choose ZIP. The quality must always be set to ‘8 bit’, since otherwise this would reduce the color depth. This would make the document unusable. ZIP is ideal for motifs with high contrasts or large, homogenous areas. JPEG can be set to five quality levels. For printable PDF documents, the ‘high’ quality setting should be selected. JPEG is suitable for real images that are rich in detail. The file size of image data compressed using JPEG is proportional to the quality. In other words, the best quality equals the biggest file. For line data (monochrome images), a total of four loss-free compression methods can be used.‘CCITT Group’ is the name given to the method used for faxes transmissions. The ‘ZIP’compression method creates the smallest documents.
Different savings depending on the color motif. Motif A without fine details, motif B with. 200
400
600
800
1,000
1,200
1,400
1,600
For compression, the following applies: The best choice of compression method and efficiency depend on the image motif.
JPEG compression in high quality is barely noticeable with most print processes – a sample print of a test file provides clarity.
Creation • Downsampling PDF Workflow 39
Downsampling The resolution of image data should be appropriate for the purpose. For printing, it depends on the screen ruling and the printing method. 300 dpi is a typical value for contone originals (color/grayscale images) in offset printing in normal quality (screen ruling 60 lines/cm). For the Internet, a value of around 96 dpi is sufficient. The resolution of linework (bitmaps) should be considerably higher, and in ideal situations should match the resolution of the imaging or printing system, e.g. 2540 dpi. Occasionally, the resolution of the image data in the PostScript print job is too high. It has either been selected too high when the user was scanning it in, or it has been changed due to scaling in the layout program. The higher the resolution, the bigger the data volume. Adobe Acrobat Distiller can reduce the image resolution to the desired value. This avoids PDF documents that are too large. The program offers three methods of reducing the image resolution:
Double the resolution is equivalent to four times the amount of data. Acrobat Distiller avoids unnecessary data ballast by downsampling the image resolution.
Methods and target values for reducing the resolution are set on the ‘Compression’ panel.
• Subsampling: Low quality, but fast. • Average downsampling: Better quality, but slower. • Bicubic downsampling: Best quality, slowest method. An output device’s RIP (Raster Image Processor) always adapts the image resolution to the value required for output. If this step is carried out in both Distiller and the RIP, the risk of a loss in quality increases. It is therefore possible on the ‘Compression’ panel to set the minimum resolution that data must have, so that reduction by Distiller takes place as effectively as possible.
40 PDF Workflow Creation • Fonts
Fonts The ‘Fonts’ panel is used to specify that fonts are to be embedded – either in their entirety or as a subset.
For the print production stage, a PDF document must have all the necessary font files embedded in it. Only if this is the case is the transfer/adoption of job data useful and reliable. The options on the ‘Fonts’ panel must be set correctly for this
to happen. In other words, the ‘Embed All Fonts’ option must be activated. The ‘Subset embedded fonts’ option enables the user to decide whether the entire font or just the characters used are to be embedded. In this situation, the
characters used (subset) are only embedded if fewer font characters have been used in the documents than are specified by the percentage. The ‘100 %’ setting therefore forces subset embedding. Embedded subsets have the advantage that an output device in the workflow is forced to use the embedded font. This method essentially avoids font conflicts. One handicap of font subsets, however, is the fact that subsequent editing of texts is only possible with restrictions if indeed at all. If a certain letter has not been embedded, it cannot be used during correction either. The disadvantage of documents with embedded subsets is that subsets of the same font type are not reorganized. All subsets remain unchanged if individual pages containing subsets of the same font are re-collated to form a single document. One subset of one and the same font would remain embedded for each page. The ‘Cancel Job’ entry for the ‘When Embedding Fails’ option prevents PDF documents from being generated with-
Select ‘Cancel when Embedding Fails’, since a document without embedded fonts cannot be used in print production.
out font information. If no fonts can be embedded, no PDF document is generated. In the section entitled ‘Embedding’, users can decide whether specific character sets are always to be embedded or are never to be embedded. Manufacturers of TrueType fonts can prevent their fonts from being embedded. In this case, Distiller would not embed that particular font. In these situations, the only option is to contact the font data’s manufacturer.
Creation • Font Substitution PDF Workflow 41
Font Substitution Adobe Acrobat also delivers a readable document if the fonts have not been embedded. The two Multiple Master Fonts ‘Adobe Serif MM’ and ‘Adobe Sans MM’ are used to generate substitute fonts. These correspond to the original font in terms of thickness, orientation, cap height and x-height. Font substitution enables PDF documents to be read on screen, even if they do not have embedded fonts. This means that PDF documents destined for Internet use can remain very small. A PDF document of this type should under no circumstances be produced as a print job, however, since the artificially generated font types would be used. The recipient of a PDF document simply needs a copy of Adobe Acrobat Reader in order to view the file. In the File menu, under the item ‘Document Properties’, the ‘Fonts’ command can be clicked to obtain further information.
Take care if the ‘Adobe Serif MM’ and ‘Adobe Sans MM’ font types appear in the font information – this document should not be produced.
The entries labeled ‘Embedded’ and ‘Subset’ indicate readiness for production. This means that the author’s fonts are retained in the document. The ‘Substitute Font’ entry, on the other hand, indicates that an operating system font is being used. If both of the abovenamed Multiple Master fonts appear as ‘Substitute Font’, this can mean only one thing – this document must not be produced.
Original fonts (top) and simulations (bottom) are occasionally almost indistinguishable from each other. To make sure, a glance in the document properties is all that is required.
42 PDF Workflow Creation • Font Locations
Font Locations Under normal circumstances, the PostScript print job contains the fonts that Distiller will be embedding in the PDF document. In exceptional cases, however, Acrobat Distiller can also access to further sources for font information. • Font folders: The ‘Settings’ menu contains the ‘Font Locations’ menu item, which can be used to assign Acrobat Distiller additional font folders. • System folder/font directory: If necessary, Distiller also uses fonts from the operating system’s font directory. In other words, it looks for fonts in the ‘Fonts’ folder in Mac OS, and the ‘Fonts’ folder in Windows. The font information available for Distiller can be viewed on the ‘Fonts’ panel which can be accessed using the command sequence ‘Settings > Job Options’. In the items listed under ‘Embedding’, users can check all the font sources that are available to Distiller. TrueType fonts that cannot be embedded are marked with a lock symbol.
Fonts belong in the PostScript file, since this is the first place Distiller looks for them.
Distiller can be assigned further font folders in which it can look for fonts.
TrueType fonts are labeled with a lock if their manufacturer does not allow them to be embedded.
Creation • Color PDF Workflow 43
Color On the ‘Color’ panel, users can set how color information is to be handled. The supplied default settings leave the color unchanged. The user can select which ICC profiles are to be used for the individual working spaces, making separate entries for grayscales, RGB color data and CMYK color data. The user can also select the conversion method if color spaces are to be converted. All color management settings can be saved in a settings file, and can then be called up at the click of a mouse. In the ‘Device-Dependent Data’ section, users can define how PostScript commands are to be handled for color separations, overprint settings, gradation curves and the screen (halftone) structure. These commands can be embedded into the PDF document or removed from it. Up until Version 4 of Adobe Acrobat, these settings only took effect when documents were being output on a PostScript output device. From Adobe Acrobat 5, users can monitor the effects of the ‘Overprint’ parameter on the screen. To do this, the overprint preview must be activated in Adobe Acrobat 5. A new feature of Distiller 5 involves the ability to factor
Changes to the color settings should only be made in agreement with the company responsible for production.
in any transfer function into the PDF document, so that the effect becomes visible on the screen. An example of the overprint preview can be found in the section entitled ‘Adobe Acrobat Version 5.0 – Prospects’.
The ‘Color’ panel is where users can define how Distiller is to handle color information.
44 PDF Workflow Creation • Advanced
Advanced This panel offers a wealth of different settings. These are the most important: Acrobat Distiller can be programmed in PostScript for special tasks using the control files ‘prologue.ps’ and ‘epilogue.ps’. Their use is activated with the ‘Use Prologue/Epilogue’ option. These control files can also be used in watched folders. In this situation, they must be activated in the watched folder settings. PostScript print files can also contain control commands that modify Distiller’s settings. This can be permitted by activating option ‘Allow PostScript File to Override Job Options’. The ‘Convert gradients to smooth shades’ option switches on idiom recognition. Distiller then detects close-lying, color-graduated objects and generates a smooth vignette.
In the ‘Document Structuring Conventions (DSC)’ section, the ‘Preserve OPI Comments’ option must be mentioned. If it is activated, OPI comments are retained in the PDF document.
Further information can be found in the Creation section entitled ‘Using OPI images’.
If OPI commands are required in the PDF document, the setting must be activated on this panel.
In certain cases, settings may need to be made on the ‘Advanced’ panel.
Creation • Watched Folders PDF Workflow 45
Watched Folders PostScript files can be converted automatically into PDF documents, since Acrobat Distiller can watch folders. They are managed with the command sequence ‘Settings > Watched Folders’. It is in this dialog box that the folders to be watched are assigned to Acrobat Distiller. Here, the ‘In’ and ‘Out’ folders are generated automatically. The ‘In’ folder is watched at freely definable intervals. Incoming files are automatically converted into PDF documents when they arrive. It is important that different conversion settings can be assigned to each folder. These can be modified for the selected folder with the ‘Job Options’ button. An existing Job Options file is loaded as a template with the ‘Load Options’ button [Creation ‘Job Options’]. Distiller saves converted PDF documents in the ‘Out’ folder. In the ‘Post Processing’ section, users can define what is to be done with the PostScript file after processing. It can be ‘Deleted’ or ‘Moved to ‘Out’ Folder’.
Every watched folder can be given its own conversion settings.
Acrobat Distiller, when installed centrally, watches folders and converts incoming files automatically into PDF documents.
Acrobat Distiller can be installed on a powerful network computer, so that the watched folders are visible to all users. In and Out folders can reside on the user’s (Mac OS or Windows) desktop – as and alias or as a link. The advantages of watched folders: All connected users can work with the same conversion settings. The workload at each individual workstation is reduced.
46 PDF Workflow Creation • Golden Rules
Golden Rules Inadequate PDF documents result in inadequate output quality – or they can ruin the output altogether. The key to avoiding this situation is simply to follow the rules. • Layout files: Layout errors often pop up in PDF documents, e.g. if pages have been designed incompletely or unprofessionally [Creation ‘Correct Layout Files’]. • Avoiding PDF Writer: Anyone using Distiller is on the right path to creating a print-ready PDF document [Creation ‘PDF Writer or Distiller?’]. • Using Adobe PS printer drivers: The latest printer drivers for Mac OS and Windows can be downloaded from Adobe’s web server (http://www. adobe.com/support/downloads/). • Using Distiller PPD: The PostScript printer drivers include the Distiller PPD. Other PPDs generate device-specific PDF documents [Creation ‘Acrobat Distiller PPD’].
• Embedding fonts for PostScript output: This ensures that Distiller receives and embeds the fonts that are actually used [Creation ‘Mac Printer Drivers’]. • Configuring Distiller correctly: The person producing the document provides the appropriate ‘Job Options’. He knows best which properties the PDF documents should have [Creation ‘Job Options’]. • Using watched folders: Watched folders centralize, automate and standardize PDF generation [Creation ‘Watched Folders’]. • Using tools: The market is becoming increasingly populated with tools for generating perfect PDF documents for the prepress stage. Enfocus offers ‘Instant PDF’, which can be used to set up printers under Mac OS and Windows. The appropriate Distiller parameters can be stored in these printers’ settings just like a test profile. As a result, customers can supply checked PDF documents – with the test settings that the print service provider supplies.
Efficient PDF generation without hitches – provided the rules are observed.
MetaDimension from Heidelberg contains a special printer driver that transfers the right parameters for professional print production in the form of Job Tickets. An overview of these tools can be found in the section entitled Production ‘Recommended Tools’.
Basics
Creation
Production
Management
48 PDF Workflow Production • The History of PDF
The History of PDF Adobe PDF has been the object of constant further development. From a document exchange file format in the office sector, it has become a production format for prepress and media production. PDF Version 1.2 appeared in 1996. This was the first time that parameters for PostScript output devices could be transported. Not only could screen rulings and angles now be retained in their entirety, but so too could color separation information. In 1999 came PDF Version 1.3, which could be used to transfer preseparated data too. PDF documents now also contained the trimming parameters that were essential for impositioning. The color information could now be prepared with embedded ICC profiles for color management. PDF documents were no longer limited to device-specific color models. Duplex image data was now just as possible as hi-fidelity color. PDF 1.4 is the latest version of this file format. For the print industry, this version offers virtually no fundamental innovations. Most of the changes involve document security, electronic forms and – most of all – the storage of structure information (tags). This latter enables content to be reused without problems.
The world of graphics can now also transport transparent objects with PDF 1.4 documents. PostScript cannot keep pace with this development. In other words, transparent objects must be converted into pixels (image data) for PostScript output. This slows down the output speed on the workstation and also in the output system. There are now two further functions available to print production and the workflow. Links can be placed in a PDF 1.4 document to other PDF documents, which in turn can contain objects and image data. The document contains a preview, which invited comparison with the OPI (Open Prepress Interface). Print control elements are flagged in PDF 1.4 documents. This treatment means that they too can now be processed, even though they are positioned outside the visible page.
PDF 1.3 satisfies the requirements of the print industry. Version 1.4 supports further small details – and transparent objects.
PDF Version 1.3: • OPI 2.0 • Separation info • ICC-based color • Trapping info (via PJTF) • Bleed, Trim, Art Box • Embedded files • Alternate images • PostScript 3 compatible PDF Version 1.4: • Transparency • Links to other PDF documents • Printer marks
Production • Generating PDF Documents Correctly PDF Workflow 49
Generating PDF Documents Correctly Production-ready PDF documents are essential for a smooth digital workflow. Errors that occur during their generation are often impossible to eliminate later on – for example if the resolution of the included image data is too low. PDF documents can be generated in different ways. The various methods are described in the section entitled [Basics ‘Generating PDF’]. The method involving a PostScript print file and its subsequent conversion using Acrobat Distiller is the most reliable. The right printer drivers and the right description file (PPD) are essential for a PostScript print file (see the section entitled Creation ‘Acrobat Distiller PPD’ and below). The different settings in the Acrobat Distiller conversion program are described in the section entitled Creation ‘Acrobat Distiller’ and below.
PDF documents must meet all kinds of different criteria – depending on where they are going to be used. Different demands are placed on PDF documents for printing than those destined for use on the Internet. On the Internet, substitute fonts are used instead of original fonts, in order to speed up the download process.
Errors when PDF documents are being generated are extremely difficult or impossible to eliminate at a later stage.
PDF documents can be generated in all kinds of different ways – but only a very few are suitable for use in the prepress sector.
Feature Image resolution: JPEG compression: Color space: Font embedding: Optimized for Internet:
Monitor
Printer
Imagesetter
72 dpi low quality sRGB no yes
150 dpi medium quality RGB or CMYK yes no
300 dpi high quality CMYK yes no
50 PDF Workflow Production • Distiller Settings
Distiller Settings Service providers should provide their customers with the right Distiller settings, in order to obtain productionready PDF documents.
‘Job Options’ are located in the ‘Settings’ folder, which can be found in the Distiller folder, under the Acrobat program directory.
Adobe Acrobat Distiller is the first program of choice for generating PDF documents for print or media production. The conversion program’s settings are very versatile, so that PostScript print files can be used to generate PDF documents for all areas of application. The conversion options are described in [Creation ‘Acrobat Distiller’] and in the following sections.
The media producer or the prepress professionals generally know which settings are most suitable. This is why, in ideal situations, they should supply their customers and clients with the default settings for Acrobat Distiller [Creation ‘Job options’]. The PDF author can then select these at the click of a mouse, so that all the necessary settings are in place.
Production and prepress businesses must therefore prepare different ‘Job Options’ files – one for each different printing method or processing workflow. These ‘Job Options’ should be provided for downloading via the Internet or sent via e-mail. The recipient saves the ‘Job Options’ in the ‘Settings’ folder. This folder is found under the Adobe Acrobat program folder in the Distiller folder.
There are weak points, however, since the user might change or simply ignore the supplied settings. This could happen to anyone, but without a tool it is impossible to know what ‘Job Options’ the author has used. As a result, an immediate check by the producer is essential once a job document has been received.
Production • Checking PDF Documents PDF Workflow 51
Checking PDF Documents A PDF document must be checked before it is fed into the production process. Adobe Acrobat, in addition to the visual checking options on the screen, also offers two further functions: • Document summary: This dialog box is accessed via the command sequence ‘File > Document Properties > Summary’. It provides much information about the document. The recipient most importantly learns how the document has been generated, and can predict whether any problems might occur. The box may also contain useful information about which program the user has used. If the PDF version used was earlier than 1.3, information that is vital for production – such as spot colors – may be missing (see the section entitled Production ‘The history of PDF’). For Internet use, the PDF document should always be optimized: ‘Fast Web View = Yes’.
Incoming PDF documents must be checked for compatibility before being fed into the production process – thus preventing them from causing any problems.
The ‘Document Fonts’ dialog box shows whether all fonts have been embedded.
• Document fonts: In this dialog box, the producer finds out whether all the necessary fonts have been embedded. On the screen, missing fonts may not be immediately recognizable at first glance. Further information on this dialog box can be found in the section entitled Creation ‘Font substitution’.
The ‘Document Summary’ dialog box reveals how the PDF document has been generated.
52 PDF Workflow Production • Automatic Document Checking
Automatic Document Checking PDF documents must be checked thoroughly before production. Adobe Acrobat alone does not offer sufficient functions for detailed, automated document checking (preflight check). Additional tools are required – known as preflight tools. They have been developed especially for the PDF file format and for use in print production. They range from Adobe Acrobat plug-ins to stand-alone, fully-automatic checking programs. Before further processing, PDF documents are checked using preflight tools for different properties. Examples of checking parameters: • PDF version. • Security settings. • Font embedding. • Font types. • Color models. • Special colors. • Image resolution. • Image rotation/scaling. • Page size. • Trimming parameters. • PDF-X/3 conformity.
Incorrect parameters would hamper output, or at least give rise to inadequate quality. If a PDF document’s image data resolution is too low, it must be regenerated. Additional tools or the ‘TouchUp Text’ tool help to embed missing fonts. These can only do this, however, if the fonts are installed in the operating system. Preflight reports flag up whether the verified documents require special treatment of any kind. If PDF documents contain color definitions in the RGB color model, for example, they must be converted into CMYK for color separations before imaging. Many preflight tools can, where necessary, change parameters, set the required values and even convert color spaces. ‘Certified’ from Enfocus is a tool that can store preflight records and processed interim stages in the PDF document. The PDF document is only classed as ‘ready for production’ if all unsatisfactory work and errors have been rectified. You can find a summary of the tools in the section entitled Production ‘Recommended tools’.
Preflight tools are essential for reliable production. They help to avoid unpleasant surprises, press downtimes and added costs.
The preflight record from ‘pdfInspektor 2’ flags up potential problems.
‘Certified PDF’ checks all documents and documents all stages of the processing chain.
Production • Converting PDF Documents PDF Workflow 53
Converting PDF Documents With Adobe Acrobat 5, PDF documents can be converted and exported in different file formats. These file formats ensure that the content can also be processed or placed with other, older application programs. The following file formats can be stored directly from Adobe Acrobat 5: • EPS (Encapsulated PostScript). • HTML (Hyper Text Markup Language). • JPEG (Joint Photographic Experts Group). • PNG (Portable Networks Graphics). • PostScript. • RTF (Rich Text Format). • TIFF (Tagged Image File Format). • TXT (ASCII text). • XML (eXtended Markup Language). Many graphics programs can open PDF documents. In most cases, this is done by converting the documents into a native file format. This means changing the content. When the document is re-saved, it is then converted back into PDF. The result is a completely changed PDF document. It is impossible to edit it in most cases if the workstation does not have the relevant fonts.
Virtually all graphics programs can import and place PDF documents – and in most cases a conversion is required.
PDF documents can be imported and opened by graphics programs (left). Adobe Acrobat 5 can convert PDF documents into various file formats (bottom).
Layout programs can place PDF pages. They use different methods for doing this [Production ‘PDF Support for Application Programs’]. It has been possible to use Adobe Acrobat to process objects since Version 4. The only requisite is that application programs for vector objects or image data or plug-ins are installed [Production ‘Editing Graphics and Images’].
54 PDF Workflow Production • Editing Text
Editing Text Extensive text corrections must be performed in the application program, and the PDF document regenerated.
Acrobat prevents text from being changed if a font subset of the relevant font type has been embedded.
With Version 4 and later, users can edit text directly in Adobe Acrobat. This function enables text errors to be corrected right up to the last minute – and even to change font attributes and font assignments. The ‘TouchUp Text’ tool is however limited to a single line of text. The ‘TouchUp Text’ tool can be used to insert new lines of text when the CTRL text is pressed. If more extensive corrections are required to the text, these must be performed directly in the application program, and the PDF document must be Text attributes can also be changed at a later stage in Acrobat, although this will adversely affect the typographic quality.
regenerated. Entire paragraphs can only be edited with plug-ins. This method is however inefficient if language management and automatic hyphenation are not available. As always, it is essential to inform the document’s author or creator, so that the corrections or additions can also be included in the original documents.
Production • Editing Graphics and Images PDF Workflow 55
Editing Graphics and Images The ‘TouchUp Object’ tool in Acrobat can be used to select image and graphics objects in PDF documents. The editing options are however limited to Move, Delete or Copy to Clipboard. Designrelated tasks cannot be performed. It is a tool that allows corrections to be made at the last minute – just like the ‘TouchUp Text’ tool. The selected objects can only actually be edited using external installed programs – one for image objects and one for vector objects. For editing purposes, the selected objects are stored in a temporary PDF document and transferred to the relevant application program. When Adobe Acrobat is installed, Illustrator and Photoshop are recognized as suitable application programs and entered into the preferences. Selected image motifs are thus transferred to Photoshop, while vector objects are transferred to Illustrator. Once editing is complete and the document has been saved in the external program, the edited objects are automatically updated in the original document in Acrobat.
In this case too, there is one limitation – if text objects are to be edited in an external program, the workstation must have the relevant fonts installed.
Objects are selected in Acrobat and transferred to external application programs with the ‘TouchUp Object’ tool.
In the ‘Preferences >TouchUp’ dialog box, users can define the application programs to be used for editing image and graphics objects.
56 PDF Workflow Production • Document Security
Document Security It should be possible to protect digital documents against the intentional removal of content. Occasionally, authors may wish to prevent subsequent modifications to their documents. Adobe Acrobat and the PDF file format offer suitable protection mechanisms for such situations. A PDF document can be protected from being opened by defining a pass-
word. The document can then only be opened with this password. Even if the PDF may be opened, it is possible to limit the editing or removal of content. The required settings are defined in the ‘File > Document Security’ dialog box. Adobe Acrobat 5 offers additional security options. With these functions, users can be allowed to remove content from and add comments to a document.
But printouts could be limited to only coarse-resolution image data. The security settings can also be protected against subsequent changes by assigning them a password. The digital signature supported by Adobe Acrobat also falls into the category of document security. In a signed document, each change is document automatically. A document that has been pro-
Printouts of protected documents can be restricted to coarse-resolution image data – job data cannot then be produced unchecked. The integrated digital signatures are used to document approvals, corrections and changes.
Digital signatures document modifications and distribute approvals.
tected against changes with a password is however difficult to use in the production process. The document and processing history, along with approvals and corrections, can be handled with digital signatures in Adobe Acrobat 5 without the need for any additional tools. For users who only need to countersign and approve documents, Adobe offers a standalone, cheaper product – Adobe Acrobat Approval. When using these various functions, the Adobe Acrobat Licensing terms and conditions apply to all users. All persons or computers must have valid licenses, even if taking advantage of Acrobat 5.0 network features such as shared folders.
Production • Color Separation PDF Workflow 57
Color Separation Adobe Acrobat 5 does not support colorseparated output. Ideally, it would be possible to at least obtain the details of the separation parameters, even if the color separations don’t occur until the RIP stage (in-RIP separation). Supercolor is an Acrobat plug-in from Heidelberg that prepares PDF files ready for printing in terms of the colors and color spaces they use. Supercolor analyzes the PDF documents and displays all the colors and color spaces used. It also displays which colors and color spaces the document contains after conversion. In the Settings, users can define which profiles are to be used for the color space conversion. Defined PDF/X Output Intents are taken into account. With the colors/ separations, it is possible to convert special colors to process colors, rename and group together colors and suppress colors at output. All settings can be stored in ‘Job Settings’ and reused.
Color separations from PDF documents are currently only obtained with the Adobe Acrobat ‘Crackerjack’ plug-in from Lantana [http://www.lantanarips.com]. This plug-in enhances Adobe Acrobat so that color separations can be generated in different ways: • In-RIP separation (PostScript commands). • Pre-separated PostScript file. • Unseparated, color (composite). • Unseparated, grayscale (conversion). • DCS 2.0 single file (pre-separated EPS file). • DCS 2.0 multiple file (multiple preseparated EPS files with preview file). ‘Crackerjack’ supports the color-separated output of PDF documents. Pre-separated DCS files can be used for impositioning systems. The plug-in also works in automatic mode with watched folders. Prior to the color separation stage, a color space conversion may be necessary – for example if the PDF documents originate from an Office program or have even been generated with PDF Writer. These documents contain color information in the RGB color model that is to be converted into CMYK. ‘Crackerjack’ has included this conversion feature since Version 4.
Color separations and color space conversions can only be handled in Acrobat through the use of plug-ins.
A further Acrobat plug-in can also perform the color space conversion from RGB into CYMK as described above: ‘Quite A Box of Tricks’ from Quite Software [http://www.quite.com]. The plug-in also offers other useful functions: subsequent compression and resolution reduction for image data, font diagnostics and freely selectable page rotation and scaling.
Supercolor prepares PDF files ready for printing in terms of the colors and color spaces they use.
58 PDF Workflow Production • Exporting PDF Documents
Exporting PDF Documents PDF documents can be stored in Adobe Acrobat 5 as PostScript or EPS files (Encapsulated PostScript). As a result, entire PDF documents or individual pages can be made available to other programs such as impositioning systems or older layout and graphics programs that cannot process PDF directly. The conversion to PostScript 3 entails virtually no losses. Conversions to older versions of PostScript, on the other hand, can entail losses. Color information must be converted according to the PostScript version being used. PostScript Level 1 files are significantly larger, since the first version of PostScript did not support compression. Adobe Acrobat 5 offers further export formats for PDF documents. In the ‘Save As’ dialog box, users can choose between PostScript, TIFF (Tagged Image File Format) and JPEG (Joint Photographic Experts Group) formats. The corresponding PDF document is broken down into pixels during export. Unfortunately, however, Adobe Acrobat 5 stores this information in the RGB color model.
Older PostScript versions cannot register all information. PDF 1.3 can be converted to PostScript 3 without losses – and vice-versa. Transparent objects are converted into pixels for PostScript.
Adobe Acrobat can now store different file formats directly. Under certain circumstances, some information can be lost, for example true transparency.
Production • Microsoft Office PDF Workflow 59
Microsoft Office More and more print job data is being created with application programs that were not conceived for prepress use. These are mostly programs that are used in office environments – the most common of which are Microsoft Office products. Adobe itself provides macros for users of Microsoft Office products, thus enabling them to generate PDF documents with maximum convenience. The point of this macro, known as ‘PDFMaker’, is to transfer as many interactive functions as possible from application programs into PDF documents, and not to provide PDF documents for printing. Microsoft Word hyperlinks or crossreferences become links in the PDF document. Automatic tables of contents are created with links that lead directly to the relevant page. Templates are turned into bookmarks. PowerPoint presentations become PDF documents containing bookmarks and overlay effects. Worth mentioning are the ‘tags’. These are embedded in the PDF document if they have been created using the ‘PDF Maker’ macro in Word. They enable con-
tent to be used in other text editing and layout programs. PDF documents that contain this additional information can be stored in the RTF file format (Rich Text Format). If the reader wishes, pagination can also be performed at the margin of the screen – a function designed for electronic books. The convenience that macros offer Microsoft Office users gives no direct advantage to the prepress stage, however.
Functions from Word become links in PDF documents – thanks to Adobe’s ‘PDFMaker’ macro.
When PDF documents are adopted from the office environment, a number of special features need to be taken into account, since the documents will contain color information in the RGB color model. This limitation applies to virtually all application programs for office or home users. The necessary color space conversion can be effected in Acrobat through the use of plug-ins [Production ‘Color separation’].
PDF documents from Office programs can be output color separated using Acrobat and plug-ins.
The ‘Prepress’ setting should not fool users into forgetting that PDF documents need to be post-processed.
60 PDF Workflow Production • Distiller as a Control Instance
Distiller as a Control Instance The PostScript page description language is now the standard for output devices in the graphic arts industry. All graphics application programs can control PostScript devices or generate PostScript files. The flexibility and complexity of PostScript occasionally causes problems for users [Basics ‘PostScript and PDF – the Differences and the Things They Have in Common’]. These problems almost always occur at inconvenient moments and in awkward places – for example during output in the imaging or printing system. PostScript problems then delay or hamper output just before production gets underway. Older sheet assembly systems analyze these PostScript files in order to rearrange the pages they contain on the print form. Occasionally, insurmountable problems can occur here too – in some
situations, the document structure of complex PostScript print files cannot be resolved. Acrobat Distiller can function as a diagnostic tool for avoiding unpleasant surprises. This software is a PostScript interpreter and behaves just like an output device. Instead of a printout, a PDF document is generated. With Acrobat Distiller, a PostScript file is first converted into a PDF document, which can be viewed on the screen using Adobe Acrobat or Acrobat Reader. Even if Distiller cannot resolve the PostScript problems, the logbook file will normally list the page number on which the problem occurred. In the next stage, Adobe Acrobat can be used to convert the PDF document back to PostScript. The advantages of this method include the fact that the new
PostScript file is reorganized and will be processed faster. Distiller has reduced the image resolution to the required value and the file size has shrunk. Acrobat embeds missing structural information, so that sheet assembly systems can better interpret the new PostScript file. This simple method maximizes profits, since PostScript errors no longer occur in expensive output systems and can thus no longer cause blockages.
Acrobat Distiller behaves just like a PostScript output device and is more suitable for PostScript diagnostics than an expensive imaging system.
Acrobat Distiller cleans up PostScript files and enables them to be displayed on the screen. PostScript exported from Acrobat is smaller and has a better structure.
129.6 MB
Distiller
16.2 MB
Acrobat
53.2 MB
Production • OPI Workflow with PDF Documents PDF Workflow 61
OPI Workflow with PDF Documents OPI (Open Prepress Interface) is a method for reducing image data on a network or for data transfer. An OPI server is the central storage location for fine-resolution image data. It uses this data to create coarse-resolution substitute images independently for the layout workstations. In the imaging and printout stages, the OPI server uses ‘OPI comments’ to detect where the fine image data is to be inserted in the output print workflow. OPI is used wherever large volumes of image data are used or where different companies share image work. OPI comments can also be embedded in PDF documents. This means that, when PDF documents are being output via the OPI server, the fine image data is re-integrated. Acrobat Distiller must be correctly set up so that the OPI comments in the PDF documents are retained. On the ‘Advanced’ panel, the ‘Preserve OPI Comments’ option must be activated. In the PDF document, the image element is marked as a coarse image with OPI comments.
PDF documents can be used in an OPI workflow – if Distiller has been correctly set up.
On Acrobat Distiller’s ‘Advanced’ panel, users must specify that OPI comments are to be kept.
62 PDF Workflow Production • Impositioning
Impositioning The PDF file format is far more suitable for impositioning than its forerunner, PostScript. PDF documents do not have to be laboriously interpreted. They can be evaluated far more easily and can be composed to form complete sheets far faster. Impositioning software must satisfy very varied requirements. Accordingly, the range of solutions available for PDF vary greatly. The products on offer range from plug-ins for Adobe Acrobat to standalone, fully-automatic solutions that work with watched folders. SignaStation® from Heidelberg, one of the most widely-used solutions in the world, imports PostScript, PDF and Delta lists, and can also generate PostScript or PDF sheets for PostScript RIPs, as well as Job Tickets for Job Ticket-based workflows. In modern PDF workflow systems, page contents and processing information are kept separate. Contemporary impositioning systems store the processing information in the form of a Job Ticket. This relieves the application program of the task of composing and calculating the entire form.
This electronic, job-specific imposition layout is only processed just before output. This method relieves the user’s workstation from calculating the form and provides the necessary flexibility if the print system has to be changed at the last minute.
PDF documents can be imposed very quickly to a form – modern impositioning systems transfer ‘Job Tickets’ with processing information.
SignaStation can impose PostScript or PDF documents to complete forms. Alternatively, the processing information is stored as ‘Job Tickets’ for the output systems.
Production • Trimming PDF Workflow 63
Trimming From PDF Version 1.3 onwards, it has been possible to store trimming data in the document. Outside the visible page limits, further information is included unseen in the PDF document. • MediaBox: ‘MediaBox’ specifies the page size that has been selected as the paper or page format. • BleedBox: ‘BleedBox’ describes the page size, including the trimming allowance. • TrimBox: ‘TrimBox’ specifies the size of the trimmed page. • ArtBox: ‘ArtBox’ specifies various other frames on the page. This additional page information is essential for impositioning systems [Production ‘Impositioning’]. The layout programs should write it into the PostScript output or the PDF document. Only this method facilitates problem-free sheet assembly. Helper programs are available for Distiller that uncover register and trimming marks from specific layout programs in PostScript files. They automatically derive the necessary information from these marks.
From Version 1.3 onwards, PDF documents can also contain trimming information.
PDF Workflow
ArtBox TrimBox BleedBox MediaBox
Additional information in the PDF document provides details on the trimming parameters.
64 PDF Workflow Production • Print Control Elements
Print Control Elements Print control elements such as register marks and test scales are positioned in the layout program or in Adobe Acrobat. From time to time, they occur for the first time later on in the RIP or at the output stage with Acrobat plug-ins. For color-separated outputs with the ‘CrackerJack’ plug-in from Lantana, a simple test scale is also possible in addition to register marks. Impositioning programs such as SignaStation from Heidelberg also generate register marks and test scales. From file format PDF 1.4 onwards, particular importance is attached to these print control elements. They are given their own identity, so that they can be distinguished more clearly from ‘normal’ displayable objects.
This special method is useful if PDF documents are being processed in the digital sheet assembly stage. The labeling system makes it clear which elements can be done away with or moved on the print form.
Print control elements are marked separately in PDF documents of Version 1.4 and later.
Print control elements are not part of the page content. They are handled separately in PDF 1.4.
Production • Screen Parameters PDF Workflow 65
Screen Parameters If the PDF document does not contain any screen parameters, all films are output with a screen angle of 45°.
On the ‘Color’ panel in the Distiller settings, the ‘Preserve Halftone Information’ option determines whether screen parameters are to be included in the PDF document.
The settings for the print screens that are to be imaged can also be hidden in PDF documents. These include the screen ruling, screen dot shape and screen angle parameters. These values are normally only set at the output stage. Users can however define these values in their graphics programs – even for individual objects.
For outputs in Adobe Acrobat, the ‘High End Features’ in the print dialog box can be used to specify whether the screen parameters from the PDF document or the parameters from the output system are to be used.
In the Acrobat Distiller settings, users can define whether predefined values are to be removed or embedded in the PDF document – with the ‘Preserve Halftone Information’ option on the ‘Color’ panel. For output from Adobe Acrobat, however, users must define in the print settings whether the PDF document’s
screen parameters are to be effective in the output device. The print settings are accessed via the ‘Advanced’ button in the print dialog box. Here, the option with ‘Emit Halftones’ must be activated. The screen parameters from the source program are only effective if both conditions are satisfied: The ‘Preserve Halftone Information’ option must be
activated in Acrobat Distiller and the ‘Emit Halftones’ option must be activated for outputs in Acrobat. If either of these conditions is not met, the preseparated PDF document will be imaged with the wrong screen parameters and will thus be unusable.
66 PDF Workflow Production • Duplex Image Data
Duplex Image Data From Acrobat Version 4 onwards, Distiller has been able to detect duplex images and save them in documents from PDF Version 1.3 onwards. The PostScript command required for outputting duplex images does not appear until PostScript 3. The PostScript command ‘DeviceN’ enables duplex image data to be described correctly in a PostScript output file. Acrobat Distiller 4 can interpret this command and convert the color information accordingly. It is essential, however, that the layout and application programs describe this information correctly with the ‘DeviceN’ command in PostScript. A typical source of duplex image data is the image editing program Adobe Photoshop. But this program too only saves duplex images in the desired way (as EPS image data) from Version 5.02 onwards.
Duplex images that have been generated and stored in an earlier version of Photoshop are however not converted in the desired way. In this case, the image motif appears multiple times on all color separations. It is therefore recommended that older duplex data be opened and re-saved in a newer version of Photoshop.
Acrobat Distiller Version 4 onwards can convert duplex images correctly – Photoshop users require Version 5.02 and later.
From Version 5.02 onwards, Photoshop users can save duplex image motifs so that Acrobat Distiller can also convert them correctly.
Production • Traps PDF Workflow 67
Traps Graphics objects must also be trapped if they lie adjacent to each other and paper white could result in print due to register differences. Traps are overlaps that were previously created using photographic technology and are now factored into digital data. Depending on the print process, different-sized traps are required. The right parameters for traps can only be set once the print process is known. In other words, the trapping parameters must remain modifiable right up to the start of production. This is also possible in ‘Job Ticket-based production’ [Production ‘Automating Output with PDF and JDF’]. Until now, it was common practice to create traps in graphics and layout programs. This method is now no longer appropriate in a PDF workflow, since trapping parameters cannot be modified subsequently. This is particularly the case for Quark XPress, which defines traps in its own, rather antiquated way using PostScript. These traps are only output if color separations are created in XPress. These color separations must then be recomposed manually back to a color PDF document using Acrobat and tools.
There are two methods available if traps are to be factored just before output into the data that is to be produced: • Pixel-oriented, in-RIP trapping: In PostScript 3 RIPs, trapping can be performed when the data is being output. This in-RIP trapping is generally a pixel-oriented, time-consuming process. Adjacent pixels are compared with each other in order to determine the traps. • Vector-oriented trapping: A faster method is vector-oriented trapping. In this situation, the objects are compared with each other. Where traps are required they are created as new objects. This method is used by ‘Supertrap’, for example, an Adobe Acrobat plug-in from Heidelberg. Supertrap won the InterTech Award from the GAT F in 2001 [see also Heidelberg products for the PDF workflow].
Quark XPress only exports traps if color separations are being created. Color XPress PostScript must be trapped later in the PDF document.
Trappings prevent paper white occurring when register differences occur.
68 PDF Workflow Production • DCS Workflow
DCS Workflow
With Impressed DCS Merger, pre-separated EPS files created in Photoshop are turned into composite EPS documents.
The ‘Desktop Color Separation’ (DCS) concept was developed over a decade ago by Quark, Inc., in order to relieve layout workstations of large volumes of data. The concept works on the principle that an image file is pre-separated and stored in the form of several EPS files. An EPS file contains the coarse image data and can be placed in the layout program. Other EPS files contain the fine-resolution color separations. On the workstation, users work only with the small, coarse-resolution layout data. The large, fine-resolution image data is only integrated into the print file at the output stage. This way, users can work faster in their layout programs – even without OPI servers [Creation ‘Using OPI Images’]. DCS image data is therefore always available pre-separated. Quark XPress will only export the fine-resolution image data if the ‘Color Separations’ option has been selected – similar to traps [Production ‘Traps’].
DCS does not correspond to a color (composite) PDF workflow.
A PDF workflow on the other hand is based on color, non-separated documents. This means that DCS image data must be recombined into a color file when it is transferred. In Quark XPress, the Xtension ‘Total Integration SmartXT’ takes care of this during output. Alternatively, DCS images can also be combined in Adobe Photoshop or with ‘Impressed DCS Merger’.
Production • PDF Support for Application Programs PDF Workflow 69
PDF Support for Application Programs A PDF workflow is based on two key technologies – PDF 1.3 and PostScript 3. The concept centers on the transfer of color documents that, at the moment of output, are processed ready for production and are color-separated. Application programs can be integrated with ease if they produce composite documents in one of the following standards – PostScript 3 or PDF 1.3 according to specifications.
Unfortunately, Quark is keeping its XPress users waiting for full support of contemporary standards. For example, traps can only be adopted in Quark XPress if color separations are printed out or saved in a PostScript file. In Quark XPress and other application programs, two further scenarios and their implementation are worth particular consideration:
• Vignettes with spot colors, i.e. if a vignette contains one or more spot colors as components. • Colorized TIFF image data, i.e. if a color is assigned to a grayscale TIFF in the layout program. If the application programs use the PostScript operator ‘DeviceN’ at this point, Acrobat Distiller can also implement these special scenarios correctly in PDF documents. All settings are retained.
Quark users are still waiting for full support for PostScript 3 and the PDF workflow.
The Acrobat Distiller converts the vignettes if the ‘Convert gradients to smooth shades’ option has been activated on the ‘Advanced’ panel of the Distiller ‘Job Options’. It also depends on the application program whether the additional information concealed in the PDF documents can be located again. In addition to traps, the most frequently measured parameters also include trimming data [Production ‘Traps’ and ‘Trimming’].
Many users exchange information in the German Quark discussion forum. The responses are not always exactly what they’re looking for (left). The Quark support database occasionally contains practical suggestions (right).
70 PDF Workflow Production • Pre-Separated PDF Documents
Pre-Separated PDF Documents The PDF workflow concept is based on color data – also known as ‘composite’ data. Documents awaiting production can contain color information from different color models and systems such as CMYK, RGB, Lab or the Pantone Matching System. The conversion into the color model of the output process only takes place if this has been defined – for example color separation in CMYK. This method offers tremendous flexibility with regard to the choice of output system. Anyone wanting to work conventionally with pre-separated CMYK data (color separations) in the PDF file format gets a PDF document with individual pages. These individual pages represent the separations for cyan, magenta, yellow and black (key) and are displayed in grayscales – digital films. These PDF documents can be imaged correctly if attention has been paid to the screen parameter settings [Production ‘Screen parameters’]. Since PDF Version 1.3, color separations are also included, so that these documents can also be processed correctly in impositioning systems.
The method involving pre-separated data is only a temporary solution. Users with a ‘composite’ approach will profit from the use of PDF workflows.
Pre-separated data, for example, enables colorized TIFF image data or traps to be adopted from Quark XPress. These latter would normally be lost in color PostScript outputs (composite) [Production ‘Traps’ and ‘PDF Support for Application Programs’].
Even pre-separated data can become PDF documents. The ‘composite’ method is however more slimline and flexible. (All figures reproduced with permission of the UGRA.The test form can be downloaded free of charge from http://www.ugra.ch.)
Production • Automating Output with PDF and JDF PDF Workflow 71
Automating Output with PDF and JDF PDF workflow systems automate the processing of job data right through to the imaging stage for print forms or the transfer of data to printing systems. PDF workflow systems are controlled with ‘Job Tickets’ (PJTF = Portable Job Ticket Format). This means that page data and processing information is kept totally separate. This method offers maximum flexibility, since the output system can be changed at short notice. The page data is stored in the page memory as PDF documents. The information these con-
tain is pre-interpreted and simply has to be prepared (rendered) for the output system. The processes in a workflow system can be automated. An operator defines the workflow sequence and assigns the necessary parameters. Incoming files are processed automatically where required – and processes that have been completed successfully trigger the start of new ones. Here are a few examples of processes that can be controlled and automated with ‘Job Tickets’:
• Verification of incoming job data (preflight). • Exchange of coarse or layout data for fine image data (OPI exchange). • Reduction in the resolution of image data (downsampling). • Removal of masked-out image sections (cropping) and data reduction to the necessary section. • Color transformation, e.g. conversion of spot colors into process colors. • Factoring-in of traps. • Display on the screen for checking purposes (soft proof ).
• Test print of individual pages and complete forms (proof, form proof ). • Impositioning of print forms. • Screening for the relevant output system (rendering, screening). • Transfer to an imaging or printing system. • Archiving on external data media.
The individual processes can be automated. The page data is transported in PDF, whereas processing commands/parameters and the job history are transported in JDF.
OPI
Color Convert
Trapping
Rendering
Page Proof
Imposition
Form Proof
Rendering
Imagesetter
72 PDF-Workflow Production • Ausgabeautomatisierung mit PDF und JDF
The standard in workflow systems is the PDF file format (Portable Document Format) for page data. In future, the job ticket format JDF (Job Definition Format) will become the standard for processing and control information. PDF workflow systems make changing the output system or print process easier. One example of this might involve converting from 4 +2 color production to digital printing (4c) at short notice. The page data remains the same. They reside as composite PDF documents in the page memory and contain all the information required. Only the processing parameters for color transformations, trapping, impositioning, screening and output need to be changed. These entries are changed in ‘Job Tickets’, and the job can begin.
The print data workflow is based on PDF – JDF is becoming the standard for job tickets. Job Data
Interpretation
Preflight
Trapping
Job Ticket
OPI
Rasterisation
Output Adobe Extreme was the first concept for the PDF workflow and centered on the separation of page data (PDF pages) and processing information (Job Tickets).
Production • Recommended Tools PDF Workflow 73
Recommended Tools There is a wide range of application programs and plug-ins available for processing PDF documents in the prepress stage. Here is an overview of the tools available: Manufacturer
Product name
Brief description
Operating system
Adobe Systems Adobe Systems Adobe Systems Adobe Systems Adobe Systems callas software GmbH callas software GmbH callas software GmbH callas software GmbH callas software GmbH callas software GmbH callas software GmbH callas software GmbH Caslon IT A/S CreoScitex CreoScitex CreoScitex CreoScitex Enfocus Software Enfocus Software Enfocus Software Enfocus Software Enfocus Software Extensis Products
Adobe Acrobat Adobe Acrobat Reader Adobe Acrobat Approval Adobe Acrobat Capture Adobe Acrobat Distiller Server AutoPilot for Acrobat AutoPilot XT FontIncluder FontIncluder Pro Server MadeToPrint XT pdfInspector2 pdfOutput Pro pdfToolbox CaslonFlow Pagelet PDF Seps2Comp Seps2Comp Separator Synapse Certify PDF Instant PDF PitStop PitStop Server PowerUp PDF PreFlight Pro
PDF generation and processing Reading and printing PDF Countersigning and approving PDF with electronic forms Converting paper documents with the scanner into fully searchable PDF Centralized PDF generation via a network Automation of Acrobat plug-ins Automated print output in QuarkXPress Automatic font embedding Automatic font embedding with watched folders Xtension to QuarkXPress for automated PDF and print output PDF verification, including PDF-X PDF color separation Collection of tools for PDF production Workflow automation PDF composition PDF separations to composites PDF separation PDF generation and processing PDF preflight & workflow Reliable PDF generation Acrobat PDF editor & preflight Automatic PDF verification & correction with watched folders Acrobat PDF editor Document verification
Mac/Win Mac/Win Mac/Win Win/Solaris/Linux Mac/Win Mac/Win Mac/Win Mac/Win Mac/Win Mac/Win Mac/Win Mac/Win Mac/Win Win Mac/Win Mac/Win Mac/Win Mac/Win Mac/Win Mac/Win Mac/Win Mac/Win Mac/Win Mac
74 PDF Workflow Production • Recommended Tools
Manufacturer
Product name
Brief description
Operating system
Heidelberger Druckmaschinen Heidelberger Druckmaschinen Heidelberger Druckmaschinen Heidelberger Druckmaschinen Heidelberger Druckmaschinen Heidelberger Druckmaschinen IMPRESSED GmbH IMPRESSED GmbH Jaws Systems (Global Graphics Software) Jaws Systems (Global Graphics Software) Krause-Biagosch GmbH Lantana Research Corp. Lantana Research Corp. Lantana Research Corp. Lantana Research Corp. Markzware Markzware Quite Software Quite Software Quite Software ScenicSoft ScenicSoft ScenicSoft ScenicSoft ScenicSoft ScenicSoft TechPool Total Integration
MetaDimension Prinect Printready System SignaStation SignaPack Supercolor Supertrap DCSMerger Distiller Secrets Jaws PDF Server PDF Creator KIM PDF Crackerjack PDF ImageWorks Stratify PDF Variform PDF FlightCheck MarkzScout Quite A Box Of Tricks Quite Imposing Quite Imposing Plus Color Central Color Central Lite Pandora Preps TrapWise UpFront Transverter Pro Smart XT
PDF RIP and workflow Automated PDF workflow based on JDF Digital sheet assembly software and workflow automation (CIP4) Full-sheet generation for packaging printing PDF-based color- and color space-conversion PDF-based trapping Conversion of DCS to composite EPS Distiller startup file Automated PDF generation PDF generation PDF sheet assembly Acrobat PDF separation Image and color space manipulation in Acrobat Layer management in PDF documents Variable date from Acrobat Preflight checker Workflow automation PDF diagnostics and processing, RGB/CMYK conversion PDF sheet assembly PDF sheet assembly for larger formats OPI print server OPI print server ‘Light’ Sheet assembly, packaging printing PS and PDF sheet assembly PDF trapping Print job production planning, JDF, CIP4 interface PS and PDF converter Xtension to QuarkXPress – DCS composite output
Win Mac/Win Mac/Win Mac/Win Mac/Win Mac/Win Mac/Win Mac/Win Mac/Win Mac/Win Win Mac/Win Mac/Win Mac/Win Mac/Win Mac/Win Mac/Win Mac/Win Mac/Win Mac/Win Mac/Win Mac/Win Mac/Win Mac/Win Mac/Win Win Mac/Win Mac
Source: http://www.impressed.de
Basics
Creation
Production
Management
76 PDF Workflow Management • Summary
Summary For four decades, the print industry and the prepress sector have been in a state of constant flux – driven by developments in technology. Digital printing and Computer-to-Plate (CtP) call for a reorganization of the prepress process chain in the form of end-to-end digitization. One prerequisite must be met if companies want to profit from these new technologies, however. Taking the manual production of print originals and forms as their starting point, they must create a perfect digital prepress stage that is automated and standardized. Since the introduction of digital print technology, the trend has been towards small jobs. State-of-the-art printing systems are having to handle increasingly varied jobs with ever-smaller job runs. Toner-based (non-impact) printing systems even make personalized print jobs possible – right down to a job run of just 1, a truly personalized print product. Gone are the days when print jobs could be acquired by sales staff simply collecting analog or digital originals personally from the customer. No print shop today can afford lengthy periods of press downtime. The press must already be starting the next job long before the salesperson has contacted
his customer by phone or via his company car. A smooth digital inflow of incoming orders is absolutely crucial for cost-effective production on stateof-the-art offset/digital presses and large-format imaging systems. Redigitized originals are only a short-term solution.
The PDF file format forms the basis for efficient data flow in the prepress stage and for transfer and communication between the customer and the production company.
Cost-effective digital printing requires a fully digitized and standardized prepress stage.
Management • Summary PDF Workflow 77
The Challenge of Diversity The media production process starts on the author’s workstation – either in the office, at the advertising agency or on another computer system. The data sources for jobs are becoming more and more varied, and the number of major graphics applications has grown to over a dozen over the last decade – all of them supporting two popular operating systems. To keep pace with software development, countless update cycles would be needed each year, this involving investments in software, training and new workflows and processes. A whole raft of application programs would need to be mastered if job data were to continue being accepted as open documents. Prepress staff must not only be able to operate all kinds of programs, but they must also be able to handle them expertly and have the knowledge necessary to spot errors in good time. Every unspotted error results in a costintensive hiccup in the company’s output systems – e.g. in the CtP or digital printing system. 15 years ago, one of the criteria for job costing involved whether full-page films or individual elements were supplied. In the latter case, this would result in costs for ‘film assembly’ or ‘finished artwork’. In the digital production of originals, too, it matters what the customer supplies: Does he supply individ-
ual files, open layout documents, fonts, graphics and image data or does he supply full-page PDF documents? The financial consequences must also be factored into the job costing and the pricing structure.
Full PDF documents or open layout data – along with all the processing input it requires? That’s the question that has to be asked.
Problem-Free Adobe PDF The Adobe PDF file format helps ensure high-speed prepress. The digital job acceptance process can be standardized with PDF – as can the remainder of the prepress workflow. Adobe Acrobat and the PDF file format are part of the standard – and not just for prepress and media production. PDF is used as much in industrial companies as in administrative bodies, government authorities and small and medium sized enterprises (SMEs). But only in the rarest of cases do users have a real overview of the possibilities offered by PDF. So companies have the task of informing, training and enabling customers and clients to transfer job data in the right way.
PDF interfaces and a PDF workflow do away with the need to master countless application programs.
78 PDF Workflow Management • Summary
And the effort is worth it – full-page and complete PDF documents. These form the basis for a more reliable production process and provide an accurate platform for costing. PDF documents that have been generated correctly contain all the necessary components in a form that is ready for production. Image data and fonts are embedded in compressed form. This ensures that job data can be transferred quickly and smoothly, and that the prepress workflow can be predicted with ease.
PDF documents contain all the required components in a form ready for production. Image data and fonts are embedded in compressed form.
Opportunities for Print and Media Service Providers The print industry will continue to change as a result of new media. The resulting, all-important question is how companies will position themselves on the market in response to these changes – as a general contractor for multimedia products or as a specialist service provider for print media? PDF plays a key role in both worlds. Specialist print service providers require smooth data-import and prepress workflows. If unpredictable events are to be
eliminated in advance, the only job transfer format can be PDF. New customers can be acquired quickly if the service provider offers a standardized procedure for transferring jobs. In ideal cases, the customer will supply the service provider with documents that have been pre-checked in accordance with the service provider’s wishes. This does away with the conventional ‘getting-to-know-you’ stage for the first jobs – and also makes the installation of new programs and fonts unnecessary.
The reorientation process for prepress companies towards multimedia can also be accelerated thanks to PDF. Printed data can be turned into digital, interactive data with minimum effort, no reprogramming and without any need for new staff. This interactive form can also include audio and video components. This way, it doesn’t matter whether the documents are to be distributed via the Internet or on CD-ROM. Cooperation, not Confrontation Errors in open job documents are often only spotted at the second glance – by which time it’s generally too late. Subsequent negotiations with customers are difficult, however, especially if costs have already been incurred or delays have already occurred. One advantage of accepting jobs in PDF is that data can be checked easily. This check could take place at the customer’s, since state-of-the-art checking tools (preflight tools) can be adapted to any specific production process. The customer obtains an agreed checking routine from the production company and can then check the documents himself using this routine. Error checking and detection is therefore shifted to the start of the production chain, and not to the end, which is so often the case. Only documents that have been checked are processed. Imme-
Management • Summary PDF Workflow 79
Page Creation
Printshop
Layout
Export or ‘Print-to-File’
Text, Images, Graphics
PostScript File
PreFlight Check
Distiller
Imposition
PDF File
RIP with Separation/Output
Check up
The PDF workflow starts at the customer’s. Only checked PDF documents can be used for costing print jobs.
ISDN Reception
ISDN Transmission
PDF File
80 PDF Workflow Management • Summary
diate contact with the customer helps ensure clarity if errors have been detected in incoming documents. At the start of the processing chain, it is easier to decide who is to make any necessary change – and under what conditions. In the creative phase, too, Adobe Acrobat and PDF facilitate communication. Dispatched or published documents an be corrected simultaneously on the screen via the Internet or intranet, and comments can be added. PDF documents can be sent and output in true color and with complete register accuracy at the customer or decision-maker’s. The only requirements include a color management system for proof prints and the ICC profiles of the production process that are embedded in the PDF documents. The PDF Workflow Concept The PDF workflow concept was originally based on a further development of PostScript from Adobe aimed at bypassing PostScript bottlenecks. Adobe Extreme was designed as the engine for PDF workflow systems. This term concealed a concept that postulated a total separation of content and processing commands. State-of-the-art workflow systems follow this method, even if they aren’t based on Adobe Extreme. Today’s trend is towards decentralized solutions, in other words smaller, local units.
PDF workflow systems create flexibility as regards the choice of output systems – even at the last minute. Job Data
Interpretation
Preflight
Trapping
OPI
Rasterisation
Job Ticket
The principle behind all modern PDF workflow systems involves the incoming PDF documents being analyzed and stored in the page memory. Any processing commands they contain are extracted and stored as ‘Job Tickets’ in PJTF (Portable Job Ticket Format). The key advantage of this is that the output system can be changed at the last minute if necessary. Because the page data is available ready for production in the page memory, only the output-specific parameters need to be modified if the output system is changed. This information contained in the ‘Job Tickets’ describes all the necessary procedures. For example: • Color management. • Trapping. • Impositioning. • Screen parameters. • Control for the output system.
Output Adobe Extreme was the first workflow concept and the engine behind early workflow systems.
Management • Summary PDF Workflow 81
This means that a job can also be output on any desired printing system at the last minute – even if it was designed for a different printing process or with additional spot colors. A few manufacturers shy away from ‘Extreme’ and its centralized concept, in order to ensure greater versatility. Two requirements are essential for success: Firstly, page content and processing information must be separated in order to offer the required level of flexibility in the prepress stage. Secondly, the system must support the PDF standard for page data and the JDF (Job Definition Format) for processing data if it is to remain open to extensions.
Safe Investment PDF workflow systems are based on standards. This safeguards investments and provides an inexpensive link to different system environments. The PDF file format is accepted in the worlds of prepress and media production. The ISO (International Standardization Organization) has agreed the PDF-X/3 standard for transferring advertising data. This means that print jobs can be transferred under standardized conditions too. The leading manufacturers have agreed on a uniform standard for processing commands. The manufacturerneutral and cross-platform Job Defi-
nition Format JDF was defined in the spring of 2000 by Adobe, Agfa, Heidelberg and MAN Roland, and is now supported by more than 60 systems manufacturers from the graphic arts industry. As an umbrella association for manufacturers, users and private persons, the CIP4 (International Cooperation for the Integration of Processes in Prepress, Press and Postpress) is forging ahead with the further development of this standard. [Link: http://www.cip4.org/]. PDF workflow systems will be compatible – thanks to standardized file formats and interfaces. This safeguards investments thanks to flexibility as regards the choice of system components.
PDF helps to open up new markets – new electronic media can be produced from printed data.
PDF File
Data Carrier
Internet
Film/Plate Imageset.
Direct Imaging
Color Laser Printer
Once PDF documents can be handled reliably, electronic media are the next step.
Multiple Use of Print Data Even apart from core business, PDF can open up new business opportunities for repro shops and print shops. The step towards becoming a media service provider is not a great one if the workflow in the prepress stage is based on PDF. PDF documents can be used on CDROM and on the Internet. Electronic media are created from print jobs in this way. Printed magazines can be archived on CD-ROM or on the Internet. Owners of PDF documents can offer their customers additional, new services and electronic media. The aim is to put prospective clients in the picture and to inform them of the range of possibilities that exist. PDF also offers publishing houses new opportunities to move into the field of electronic media production. Electronic books are already being marketed on the Internet in the PDF file format. Adobe supplies the necessary protection mechanisms and infrastructure.
82 PDF Workflow Management • Summary
Electronic books in PDF are marketed via the Internet. Protection and transfer mechanisms are supplied by Adobe [http://www.ebooks.com/].
Making the Breakthrough Easier In the print and media production industries, PDF is indispensable. Even in administrative bodies and government authorities, PDF is becoming the standard. Aspiring PDF authors need nothing more than the Adobe Acrobat package to get started. The Acrobat workstations in the prepress stage can be upgraded with a handful of add-on modules. These ‘plug-ins’ enable error checks and the productionspecific modifications. Even subsequent trapping and color separations are possible. The investment costs are then only a fraction of those that companies were used to in the PostScript age.
All process stages in the prepress are mapped in a PDF workflow system. This means that performance can be increased on a module-by-module basis and adapted to changing circumstances. The more output systems a production facility runs, the faster a PDF workflow system will pay for itself. And the greater the modularity of the PDF workflow system, the better it can grow to handle changes and to reflect the company’s progress. Heidelberg has developed excellent solutions, tailored to the needs of modern prepress businesses, media service providers and print shops.
These solutions are set out in the section entitled ‘Heidelberg Products for a Smooth PDF Workflow in the Print Industry – Based on PDF and JDF’.
PDF facilitates communication and production – as a digital and cross-media master.
Photographers
Retouchers
Authors
Lecturers
Layouters
Internet
CD-ROM Presentations
Digital Media-Neutral Master
Direct Imaging
Computer-to-Plate
Computer-to-Film
Management • Heidelberg Products for a Smooth PDF Workflow PDF Workflow 83
Heidelberg Products for a Smooth PDF Workflow in the Print Industry – Based on PDF and JDF The print industry is now being influenced increasingly by technology-driven trends. The average run size of each print job is falling, although the general pressure to complete the job quickly is rising. In order to control the entire prepress – press – postpress production chain efficiently, Heidelberger Druckmaschinen AG (Heidelberg) is offering companies in the print industry a modular workflow known as Prinect®. It is based on Adobe PDF and JDF, and with the ‘Prinance’ component also contains tools for costing and job processing. Prinect offers media service providers and print shops their first ever opportunity to network their company entirely digitally, harmonize processes and accelerate the entire production chain significantly. Prinect’s prepress components include Jetbase®, SignaStation, MetaDimension, Prinect Printready System and Delta Technology ™.
Jetbase – Professional Asset Management Devised to channel and organize the rapidly growing streams of data for prepress production reliably, Jetbase is a modular and scalable solution for archiving, rearchiving and distributing large streams of data automatically on a network. Jetbase represents an excellent interface between the author’s desktop and the print shop. The customer’s PDF files are received via the Internet and are forwarded automatically to the production stage. In the Prinect workflow these are administered in a job-specific context.
SignaStation – Imposed Forms and Job Ticket Instructions The SignaStation software is far more than just an impositioning system. Ever since DRUPA 1995, SignaStation has been able to generate the CIP4 Print Production Format (PPF). This was the first time that data that needs to be recorded in the prepress stage or is created by some other means could be used in an unbroken chain for printing and finishing. CIP4 PPF information has since been controlling the ink zone settings for presses, cutters and folders. In the Prinect workflow, SignaStation produces imposed print sheets based on Delta lists, PostScript files and PDF files. For Job Ticket-based workflows, the template is output as a Job Ticket. In both cases, SignaStation generates CIP4 PPF data for the presses’ AutoRegister, for CompuCut and for CompuFold. In the print and finishing stages, this information enables make-ready times to be cut and process reliability to be increased, since the data is transferred automatically.
Prinect Printready System – the JDFBased, Automated PDF Workflow The Printready workflow system is ideal for linking prepress production processes. Using JDF and PDF data as a basis, it automates all the stages of the workflow such as color management, trapping, proofing, interactive impositioning and final output to film or plate. In conjunction with Jetbase, SignaStation, MetaDimension and Delta Technology, it supports all workflow and archiving tasks. Prinect Printready System does more than other workflow systems, since the perfectly coordinated interaction between the server and desktop components offers impressive new levels of automation. The Printready Cockpit enables various job routines to be merged in the form of group templates from any workstation. The user defines once only which sequences are to be grouped together into a self-contained workflow plan. After this is done, a simple click of the mouse launches the fully-automated PDF workflow.
84 PDF Workflow Management • Heidelberg Products for a Smooth PDF Workflow
Internet
Management
Production Prepress
Postpress
Press
Speedmaster
Sunday
Stitchmaster ST 400
Imagesetter Folding in general
AutoRegister
Form proofer 1)
Workstation 1)
Omnicon Prinance (MIS)
Internet Portal
DataControl
JetBase
SignaStation
Printready System
MetaDimension/ DeltaTechnology
Prepress Interface
Plate Image Reader
Jukebox
Cutting in general
ImageControl
CP2000 Center AxisControl Compucut
Compufold
Compustitch
Internet
Production Workflow
Ethernet
Management Workflow
1) Non Heidelberg Products
Even on routine jobs with standardized production stages and processes, the Printready System can offer significant advantages. Because each component in the Printready workflow system can be acquired individually and used in a totally modular way, a fully-automated, end-to-end workflow can be put together gradually. Prinect Printready System also features an interface to Prinance, thereby providing a link to costing and bookkeeping activities.
MetaDimension – the Modular PDF Workflow The Adobe-based RIP can be used in the Prinect Printready System either as a separate, modular PDF workflow or as an output RIP. This enables PS and PDF jobs with high output speeds to be imaged on CtF and CtP recorders. Color and form proofs can also be generated directly from the workflow system.
The workflow with MetaDimension is simplicity itself. The user defines the processing rules and workflows and uses queues to determine what is to be done with incoming data. The processing rules are defined with the Portable Job Ticket Format (PJTF), e.g. the resolution, screening, in-RIP trapping and so on. What’s more, the stages can also be defined in a JDF. This supports the seamless integration of MetaDimension into the Prinect Printready System.
With their ability to import and export 1-bit TIFF data, MetaDimension and MetaShooter ™ offer users almost endless possibilities for linking output systems from Heidelberg and thirdparty workflows. What’s more, MetaShooter enables printing plate data to be stored, thus making it possible to repeat a plate output easily at any time at the press of a button.
Management • Heidelberg Products for a Smooth PDF Workflow PDF Workflow 85
Supertrap – for NativeTrapping of PDF Documents Heidelberg’s Supertrap solution, which won the GATF InterTech Award, is currently the only software on the market that traps PDF documents natively – i.e. traps are created interactively in the original PDF in Adobe Acrobat directly. This means it does not matter whether the PDF document originated in Quark XPress or from an Office application. Quark XPress does not provide any traps if color PostScript data is used. Supertrap, on the other hand, supports a truly composite PDF workflow with PDF documents from Quark XPress. There are also many other applications that are unable to supply trapping parameters – the most common of which include Office documents, which must be converted into the CYMK color space and trapped subsequently. With the Supertrap plug-in, however, documents from Office applications can also be trapped at a later stage in Adobe Acrobat. The basis for trapping calculations is the ‘neutral density’ of the colors, the software taking into account many design combinations. One great advantage is the lightning-fast calculation. The application uses ICC-based color management, and even special colors, metallic inks and varnishes can be trapped.
The main menu of Supertrap Plus: a very comfortable user interface for PDF-based trapping.
Supercolor Supercolor from Heidelberg is the Adobe Acrobat 5.05 plug-in that enables colors and color spaces in PDF documents to be converted into a printable format. All device-dependent and deviceneutral color spaces are converted into the output color space using the rendering intent and a PDF-X/3 output intent. Colors give rise to many possibilities for change. As a result, special colors can be renamed, grouped together or deleted. Special colors are converted into process colors using the formula in the PDF or through the inclusion of global color charts. Supercolor displays the current status in a clearly structured form and, based on the individual settings, also the target status of the colors and color spaces in the PDF. Supercolor uses the Heidelberg Color Management Engine and offers a host of other functions for enhancing the printability and quality of PDF files. These functions include extensive settings options for black retention and overprinting.
The ‘Supertrap’ plug-in is the only solution for trapping PDF documents in Adobe Acrobat.
Delta Technology – Effective Integration of Prepress Production With more than 8,000 installations worldwide, Delta Technology is a true classic among Heidelberg’s workflow systems. With the groundbreaking R.O.O.M. (Rip Once Output Many) concept and Delta Lists (the reliability of which is already legendary), Delta Technology has ensured that the workflow idea has been able to establish itself across the entire print industry. In the Prinect workflow, Delta Technology integrates prepress production for Heidelberg’s recorders, proofers and DI (Direct Imaging) printing units into the comprehensive workflow and frontend concept.
86 PDF Workflow Management • The Approved PDF-X Standard
The Approved PDF-X Standard The sections that deal with generating PDF documents [Creation ‘Acrobat Distiller’] describe the various parameters are relevant for this process. As a result, there are numerous ways of generating different PDF documents. In the USA, efforts were begun to establish a standard. The American CGATS (Committee for Graphic Arts Technologies Standards) gave ANSI, the American National Standards Institute, recommendations on how a secure PDF should look. The resulting draft standard was known as PDF-X/1 (ISO 15930-1). Typically American procedures were adopted. Image data, for example, was to be integrated as a bitmap format in the TIFF/IT file format. New methods were ignored – for example the transfer of color information into device-neutral color spaces. PDF-X/1 assumed four process colors.
The Swiss EMPA and the German Federal Print and Media Association (Bundesverband Druck und Medien) stepped in with a better, future-focused draft that offered greater flexibility. Their efforts gave rise to the ‘PDF-X/3’ (ISO 15930-3). PDF-X/3 is now being used increasingly as the standard for transferring print and advertising jobs. To ensure a reliable PDF workflow, customers and service providers simply have to agree to observe the PDF-X/3 standard. Every employee can check incoming documents to verify that it adheres to this standard. Some tools for checking standard conformity are available free of charge [Production ‘Recommended tools’].
‘pdfInspektor’ from Callas checks adherence to the PDF-X/3 standard.
Innovations in PDF-X/3 • Draft standard of ISO 15930-3. • File format PDF 1.3. • Duplex image motifs supported. • Vignettes in spot colors supported. • Color management based on ECI (European Color Initiative) recommendations. • Color definitions possible in CIE Lab. • ICC profiles permitted. • Can be used more universally than PDF-X/1.
Management • Adobe Acrobat Version 5.0 – Prospects PDF Workflow 87
Adobe Acrobat Version 5.0 – Prospects In the spring of 2001, the fifth version of the Adobe Acrobat package appeared. One key function helps contractors in the print industry to avoid a known problem that gives rise to many complaints – and this function is an overprinting preview. Until Adobe Acrobat 4, a PDF document only revealed its true features on the PostScript output device. The PostScript commands embedded in the PDF document could neither be seen on the screen nor or an output device that did not support PostScript. One common example: The ‘overprint’ attribute was incorrectly set for one color – yellow, for example. On the screen and on most inkjet or laser printers, a yellow area appears. But only at the plate imaging or digital printing stage does it become apparent that the yellow areas are not trapped – by which time it is far too late. The ‘Overprint preview’ function in Adobe Acrobat 5 represents this setting correctly on the screen and on non-PostScript output devices. At first glance, Adobe Acrobat 5 does not have much in the way of anything new to offer the print industry. It is now possible to output large pages on smallformat output devices by printing them
The ‘Overprint preview’ function reveals all: The user had set the yellow color to ‘overprint’. This is how the overprinting yellow area looked on the screen and on non-PostScript output devices before Adobe Acrobat 4 came onto the scene.
in parts. But key information is still lacking, for example the output of color separations – or at least the parameters for the separation process in the RIP (in-RIP trapping). With Acrobat Version 5, Adobe has taken a major step towards meeting Office users’ needs. The company plans to grow its sales on a market that is disproportionately larger than the print industry and the media production sector. In other words, media production will take place everywhere in the future – and that includes office environments. The prepress stage benefits from this, since Office users will be compatible with prepress workflows faster, thanks to Acrobat 5, and will then be just one step away from the final PDF document. These individuals will therefore include all users of Microsoft’s Word for Windows. In ideal situations, if they are provided with the right presettings for Acrobat Distiller, users can generate PDF documents that are ready for production. The advantage of this is that authors and customers can see on their screens or workstation printers exactly how the document will look when it is printed.
88 PDF Workflow Management • Adobe Acrobat Version 5.0 – Prospects
Adobe Acrobat 5 supports communication with customers and clients. The ‘Online Comments’ concept is compelling – offering an ability to open the required PDF document via the Internet, append comments and then close it again without needing to spend any time worrying about filenames, storage locations or transfer to the author. Communication is thus greatly simplified. Many people working on a PDF document can correct it and append comments simultaneously. Version 1.4 PDF documents from Adobe Acrobat 5 can contain more than just displayable objects. Additional data provides information on the document structure. ‘Tags’ make the content of PDF documents more dynamic and reusable. It can be saved in many different formats – e.g. as HTML (Hyper Text Markup Language) for the Internet, or as RTF (Rich Text Format) for word processing programs. Thanks to these ‘tags’, a paragraph remains a paragraph, and a break does not become a disruptive hyphen. As a result, PDF is more attractive as an archive format for print forms. Anything saved in the Adobe PDF file format can be used with more diversity and more often – either via export and import or as a placed element. In urgent cases, PDF documents for antiquated application
programs can be stored in the EPS file format compatible with up to PostScript Level 1. The document security of PDF documents has also increased with the new version. Adobe Acrobat 5 enables the author to effectively safeguard his intellectual property. With Adobe’s ‘PDF Merchant’ technology, electronic books can be protected and sold simultaneously in PDF format. Every buyer receives his own key for his book – customized only to work with the buyer’s system environment. Authors who do not want to become publishers of electronic books can also profit from the security offered by PDF. Version 4 of Adobe Acrobat introduced digital signatures. The electronic equivalents of personal signatures are changing how forms are used and how we interact with the authorities. US citizens can submit their tax returns as PDF documents – and have been able to do so for many years now. But even in the Old World, digital signatures are changing the way people deal with authorities. New legislation governing how public bodies award contracts, changes the signature law and cost pressures are all playing their part in making this possible. In future, public departments will put their contracts
out to tender using digital technology. The tendering documents will be sent in the form of a PDF document. The offering party will affix a digital signature to the document and return it with his bid. [http://www.e-vergabe.info/]. But why shouldn’t this also be possible for customers and contractors in the world of publications and print jobs? The days of illegible fax messages that trickle through telephone lines are numbered. PDF documents and Acrobat tools are an exciting means of communication for daily business. Digital signatures offer the necessary security, while comments ensure speed. In the prepress stage, Adobe Acrobat and PDF are indispensable. Even in media production, Adobe Acrobat 5 makes things more convenient, more reliable and faster. PDF will continue to change the faces of the communications industry, the exchange of information in office environments and dealings with authorities.
Recommended sales price: 28.50 €
Trademarks Heidelberg, the Heidelberg Logo, Jetbase, Prinect, SignaStation and Stitchmaster are registered trademarks of Heidelberger Druckmaschinen AG in the U.S. and other countries. AutoRegister, AxisControl, Compucut, Compufold, Compustitch, CP2000 Center, DataControl, Delta Technology, ImageControl, Internet Portal, MetaDimension, MetaShooter, Omnicon, Prepress Interface, Prinance, Prinect Printready System, Speedmaster, Sunday, Supercolor and Supertrap are trademarks of Heidelberger Druckmaschinen AG in the U.S. and other countries. Apple, LaserWriter, Mac and Macintosh are registered trademarks of Apple Computer Incorporated. Adobe, the Clearly Adobe Imaging Logo, Acrobat, Acrobat Distiller, Acrobat Reader, Adobe Extreme, Illustrator, InDesign, PageMaker, Photoshop and PostScript are registered trademarks of Adobe Systems Incorporated. AdobePS is a trademark of Adobe Systems Incorporated. All other trademarks are property of their respective owners. Subject to technical modifications and other changes.
Expert Guide 11 • 2002
PDF-Workflow 00.993.6105/01 en
Publishing Information Printed in: 11/02 Author: Thomas Müller Photographs: Heidelberger Druckmaschinen AG Platemaking: CtP Printing: Speedmaster Cover: etabind (patented) Fonts: Heidelberg Gothic, Heidelberg Antiqua Printed in Germany Copyright © Heidelberger Druckmaschinen AG, 2002
PDF-Workflow
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