Print production doc

By Pranav Rao

Printing and Production Process

A Primer for Printing Technology and the Production Process

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Aknowledgement Production process has been an integral part of our graphic design learning at NID, and I would like to express my gratitude towards our anchor faculty Dr. Tridha Gajjar for organinsing the course and guiding us in the right direction, also I would like to thank Mr. Bharath Suthar for his sincere guidiance and patience, through the course and introducing and helping us understand the various aspects of printing, I would also like to thank Prof. Tarun Deep Girdhar for providing us the facilities of print lab for exploring and experimenting with the various print techniques.

My sincere gratitude towards the staff in the print lab for helping us and guiding us throughout the practical sessions, including Hasmukh bhai, Sachin bhai, and Shirish Bhai.

Pranav Rao M.Des. 2016

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Index Chapter 1:

Press

03

Chapter 2:

History of print

04

Chapter 3:

Types of print

07

Chapter 4:

Impact Printing (Conventional)

08

Chapter 5:

Non-Impact Printing (UN-conventional)

26

Chapter 6:

Pre- Press

31

Chapter 7:

Halftone

33

Chapter 8:

Colour

40

Chapter 9:

Post Production

57

Chapter 10:

Paper and Binding

58

Chapter 11:

Ink

69

Chapter 12:

Imposition

75

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Print Production

Press

The printing press was invented in the Holy Roman Empire by the German Johannes Gutenberg around 1440, based on existing screw presses. Gutenberg, a goldsmith by profession, developed a complete printing system, which perfected the printing process through all of its stages by adapting existing technologies to the printing purposes, as well as making groundbreaking inventions of his own.

Press in the print production process referes to the actual printing operations where in the matter is printed on the given substrate without any errors.

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Print Production

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105

200

Invention of paper

Woodblock printing

1440

1430s

1040

Printing Press

Intaglio (Gravure)

Moveable type

1796

1837

1843

Lithography

Chromo lithography

Rotary Press

1884

1875

1873

Hot metal type setting

Offset printing

Flexography

1907

1938

1951

Screen Printing

Xerography

Inkjet printing

1969

1968

1960

Lazer Printing

Dot Matrix Printing

Photo typesetting

1984

1993

3D Printing

Digital Printing

Print Production

History of Print Movable Type:

Intaglio:

Printing Press:

Lithography:

Chromo Lithography:

Rotary Press:

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Metal Type each character is cast separately and placed together to make a block of text.

Drum based printing where the printing area is engraved on the surface.

A printing press is a device for applying pressure to an inked surface resting upon a print medium thereby transferring the ink.

Is a method of printing originally based on the immiscibility of oil and water. The printing is from a stone (lithographic limestone) or a metal plate with a smooth surface.

This type of colour printing stemmed from the process of lithography, and it includes all types of lithography that are printed in colour.

A printing press in which the images to be printed are curved around a cylinder. Printing can be done on a large number of substrates, including paper, cardboard, and plastic.

Print Production

Flexography

Offset

Hot metal

Screen printing

Ink Jet

Laser Printing

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Printing process which utilizes a flexible relief plate. It is essentially a modern version of letterpress which can be used for printing on almost any type of substrate, including plastic, metallic films, cellophane, and paper.

A commonly used printing technique in which the inked image is transferred from a plate to a rubber blanket, then to the printing surface.

This method injects molten type metal into a mold that has the shape of one or more glyphs.

A printing technique whereby a mesh is used to transfer ink onto a substrate, except in areas made impermeable to the ink by a blocking stencil.

A printing technique that recreates a digital image by propelling droplets of ink onto paper, plastic, or other substrates.

A printing technique that recreates a digital image by repeatedly passing a laser beam back and forth over a negatively charged cylinder called a “drum� to define a differentially charged image. The drum then selectively collects electrically charged powdered ink (toner), and transfers the image to paper.

Print Production

Printing Conventional

Un conventional

Screen

ElectroPhotography

gravure

Ionography

Lithography

Magnetography

Offset Dry Offset

Thermoraphy Laser Printed

Letterpress Flexography

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Print Production

INk Jet

Types of Print Printing is a process of production of type and image typically With ink on paper using a printing press.

It is often carried out as a large scale industrial process and is an essential part of publishing.

Conventional

UN-conventional

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Print Production

Conventional methods of printing refers to printing techniques such as offset, flexography, letterpress, serigraphy etc.

A differentiating factor in conventional method of printing is the use of a “master� which is an image carrier that is used for printing multiple copies, making it cost effective for mass printing. The process used in printing is transfer of ink through the use of pressure. Depending on the printing technique the master can be re-used.

Generally used for printing multiple copies

Unconventional printing makes use of the non-impact printing technique, and therefore does not require a master or an image carrier. The printer either automatically creates an impression of the original in its memory, which it then uses to recreate multiple copies.

Conventional Printing Letterpress

Letterpress is a form of relief printing and was invented in the 15th century by Johannes Gutenberg , it was the normal form of printing text in the mid-15th century until the 19th century and remained in wide use for books and other uses until the second half of the 20th century.

Letterpress printing remained the primary way to print and distribute information until the 20th century, when offset printing was developed, which largely supplanted its role in printing books and newspapers. More recently, letterpress printing has seen a revival in an artisanal form.

• Letterpress is the oldest type of printing.

• Movable Metal type is used to

compose text. In the layout.

• Relief blocks of zinc are used for

images in the layout.

• Elements are assembled together to create a form.

which is locked inside a metal frame called “Chase”.

• A half Inch margin needs to be left for the gripper margin

to hold the paper in this area printing is not possible

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Print Production

Flexography

Flexography is a form of printing process which utilizes a flexible relief plate. In 1890, the first such patented press was built in Liverpool, England, the water based ink smeared easily and therefore,In the early 1900s, presses using rubber printing plates and oil-based ink were developed.

It is essentially a modern version of letterpress which can be used for printing on almost any type of substrate, including plastic, metallic films, cellophane, and paper.

A flexible master is used to create an impression in the substrate as a photopolymer plate can print better than a metal plate as it can press against a substrate without damaging it. A special anilox roller is used to transfer the ink on to the master as the ink is very thin and needs to be transfered in specific quantity for fine printing

Substrates which are printed on are usually non porous plastics as flexography is suitable for printing on thin flexible soft and hard films, and gained popularity as a method of printing on cello-tape.

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Print Production

Anilox roller: This is what makes flexography unique. The anilox roller meters the predetermined ink that is transferred for uniform thickness.

It has engraved cells that carry a certain capacity of inks that can only be seen with a microscope.

These rollers are responsible to transfer the inks to the flexible-plates that are already mounted on the Plate Cylinders.

Lithography

The process used in printing are planography i.e. printing and non printing area are at the same surface, but with different chemical and physical surface properties.

The areas to be printed attract ink image area the area not to be printed is hydrophobic.

During the press run, the plate is charged twice; ďŹ rst by a set of dampening rollers that apply a coat of dampening solution and second by a coat of the inking rollers.

During this process the image areas have been charged to accept ink and repel water during the dampening. The same happens to the non-image areas that start repelling ink as they are coated with water.

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Print Production

It is based on the principle that grease and water repel, area to be printed and the areas not to be printed lie on the same level.

Offset

Lithography paved the way for modern day Offset printing.

Offset printing is a commonly used printing technique in which the inked image is transferred from a plate to a rubber blanket, then to the printing surface.

When used in combination with the lithographic process, which is based on the repulsion of oil and water, the offset technique employs a flat image carrier on which the image to be printed obtains ink from ink rollers, while the non-printing area attracts a water-based film keeping the non-printing areas ink-free

Perfecting Press A machine that can print on both sides of the paper in a single run.

Offset printing has further been developed into digital offset, direct ink, and dry offset. And has been made more economical with the advent of the CTP machines for plate making.

Trapping to avoid miss registration the colour layers are made to overlap

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Print Production

Pros and COns of Offset

Advantages of Offset printing • •

• •

•

•

Inexpensive for large quantities High quality print with 4 to 6 colour printing Widely available Able to print on a variety of papers and boards The rubber blanket stops the abrasive surface of the paper from wearing off the printing plate, and therefore the master can be used more times Able to print on both sides of the paper in one pass

Dis-advantages of Offset printing • Slightly inferior image quality

compared to Gravure • Print can bleed in non-image/

background areas when

developed plates are not cared for properly.

• Cost and Time intensive

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Print Production

Print Run Long run 1 to 3 lack copies Medium run 1 lack copies Short run 10,000 copies

Dry Offset Printing

Dry offset uses a relief printing plate that transfers or offsets multiple colours to a rubber pad or blanket, the blanket then transfers an inked image to a substrate.

• • •

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Relief plate is made of nylon Does not use water Dry offset is cured (Set) onto the substrate using high intensity ultra violet light.

Print Production

Digital Offset Printing

Printing in a Digital Offset happens in the same manner as a printer, only the plate making process is changed, there is no requirement to add an external plate the machine is capable of making its own plate and using it. this is done with the help of a unique plate which has two layers 1st layer is made of silicon and the 2nd layer is made of a material that attracts ink.

The laser burns the top layer and reviles the bottom layer which is then used as a master to print on paper.

Hp Indigo- DIGital Offset

- - - -

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No plate is required, it works on the bases of a photosensitive drum.

Based on liquid ink and a thermal offset system to print the image.

Cost of printing is variable, according to the job.

Suitable for proofing. and printing in small quantity.

Print Production

Can’t print beyond A3 size

Intaglio / Gravure Printing

Gravure is a type of recess print which has a drum with multiple grooves which hold the ink and transfer it to the substrate.

In intaglio printing, the lines to be printed are cut into a metal plate by means either of a cutting tool called a burin, held in the hand – in which case the process is called engraving; or through the corrosive action of acid – in which case the process is known as etching

Advantages of Gravure Gravure Provides high quality print, with fine edges, and is suited for long run as the master is expensive to create and lasts for a long time.

Disadvantage of Gravure All images both halftone and line art (Text are) broken into dots.

Intaglio uses variable depth of the cell to print different intensity of colours 16

Print Production

Doctor Blade: The doctor blade scrapes the Gravure cylinder to ensure that the predetermined ink amount delivered is only what is contained within the engraved cells

Screen printing

Screen print is a form of stencil printing, developed in China in the 960 and was introduced to europe in the 1910 where in they experimented with photo reactive chemicals.

While earlier the screens were made of silk today screen printing has evolved to use photochemicals to expose originals on screen.

•

•

•

•

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Plate consists of a fine mesh such as nylon, polymer or wire mesh.

Non printing elements of the mesh is blocked by a photochemical coating, hardened with light Screen plate is covered with ink and a squeeze is passed over it.

The pressure of the squeeze makes the ink pass through the open areas in the mesh and reach the substrate lying below

Print Production

Mesh is based on threads per inch, which can range from 25 to 500 Special inks such as glitter, UV e.t.c come with instructions such as the thread count and the drying time PVC ink is used to print on Plastic surfaces and now also on normal paper, as it is the fastest to set

Pros and Cons of Screen

Advatages of screen printing •

•

•

• •

Screen printing is the most versatile of all printing techniques.

Can print on any surface in various orientations Thickness of the ink can be increased which is not possible in any other printing method.

Wider range of ink and dye can be used.

The type of fabric used to create a screen can be changed depends on the requirement

Dis advatages of screen printing • •

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Print Production

Do not produce high quality Ink takes more time to dry

Steps to prepare a screen

1. Degrease 2.

Wash with water

3.

Apply photochemical coating

4.

Dry in the driers

5. *do not touch with hands post drying* 6.

Expose the screen to light

7.

Harder the light faster the screen is ready 8.

Wash in water

9. Print

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10.

Clean the Ink from the screen

11.

Store the Screen in a cool dry place with out sunlight

Print Production

Degrease: To remove dust and oil marks

Manual Stencil

Handcut

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Print Production

Screen coating is used to print the non-image area Which prevents the ink from flowing through those holes This is suitable only for 100 prints

Screen is covered with foil, sticker paper, or drawing ink, as means of blocking the light from hardening the image area.

Photochemical Direct

Direct in direct

Direct in direct

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Print Production

Photochemical screen coating + Ammonium bi chromate.

Makes the screen photo sensitive. It is applied on the screen using the coater, which is a steel appliance which is either semi-circular or V shaped.

Makes use of a croamlin sheet Chromelin Is not naturally photosensitive, in order to use the sheet ammonium bi chromate needs to be added. Post this the plate is ready for exposing to make a screen. Chromelin makes sure sharper lines are produced in a normal screen as parts of the grid where in small parts inside a grid is left fall off or get wet and are washed off creating a jagged edge.

A naturally photosensitive sheet is used which id first exposed to the positive and developed and then pasted on to the frame.

Squeegee 1.

Square edge basic printing

2.

Rounded edge more ink deposition

3.

U shaped for heavy ink deposition used for textile

4.

V shape for texture surface

5.

Bevel edge for printing used on glass

6.

Ceramic surface

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Print Production

1

2

3

4

5

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IDENTIFICATION OF PRINT OF MAJOR cONVENTIONAL PRINTING PROCESSES

Letterpress

Offset

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Print Production

•

•

•

The edges of the text will show ink squash due to heavy pressure Due to heavy pressure, at the back of the paper slight indentation will be seen Ink intensity is higher compared to offset printing, due to direct transfer of ink

• • • •

Impression will be even in text and halftone Lines and text will be sharp and has clear outlines Solid colours are evenly inked Better text reproduction than gravure

Gravure

Screen

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Print Production

• •

•

Edges of the text will not be sharp shows jagged edges Reproduction of halftone dots is very precise because they are in offset printing The image quality is better than that achieved with offset printing

•

• •

Due to heavy ink deposition, it shows slightly raised impression.

Ink intensity is also high and even Text is relatively blurry and low compared to offset

unConventional Printing Xerography

Electro photography/ Electrostatic Printing / Xerography/ Xerox.

Invented by Chester Carlson in 1937 and developed by Xerox Corporation. is a form of digital print.

Laser copier works like combined scanners and image setter by scanning the image on to an electrostatic drum.

•

Artwork is placed face down on a glass plate and is illuminated by fluorescent light which travels the length of the image.

•

The reflected images is directed through the lens to a electrically charged drum.

•

This charge leaks away where light from the image fallen on the drum.

•

A resin based powder called toner is attracted to the image areas

•

This pattern of toner is transferred to the sheet of paper, where it is fixed fused by heat.

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Print Production

Every time a print is to be made a new impression is made on the surface of the drum and reproduced, there is no way to store the impression other than as a digital file.

Collotype

Collotype is an impact based printing Collotype is a screenless planographic technique for high quality reproduction Invented in the 19th century Formerly collotype was finest technique of the reproduction of paintings

• A glass plate is first coated with light sensitive gelatin solution • Then exposed to continuous-tone negatives • Then soaked in glycerin, which is absorbed most in the

non-hardened areas • Hardened area accept the ink, and the plate can be used

to print a few thousand copies of the positive image.

{Material of the paper is photo sensitive which helps

achieve gradation in colour without the use of halftone

or breaking the image down to dots}

Wherever the light passes through the negative and meets the gelatin, the gelatin cracks, the grey is produced as the parts where the light intensity is low cracks less and the parts where in the light intensity is high cracks more.

Post cracking the plate is exposed to glycerin which washes off the gelatin and feathers the cracks which creates the smooth transition of the greys.

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Print Production

Reticulation The phenomenon of cracking the master.

Once glycerin is applied, the same process of lithography is followed.

Thermography

Thermography is an unconventional print technique which relies on heat to create the letters or images on a sheet of paper.

It produces a glossy, raised lettering by fusing thermographic print.

The text is first printed and then is coated with a fusible resin powder, when it passes under infrared light the resin pigment is fused to give a hard raised image.

Not appropriate for printing halftones or large areas of colour, which are likely to have a pitted or mottled appearance.

Edges of the text is not sharp and clear

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Print Production

Ink jet printing

Is a type of digital print, the concept of ink-jet printing originated in the 20th century, and the technology was first extensively developed in the early 1950s.

In an ink-jet printer the image that needs to be printed is created by small droplets of ink that are propelled from the nozzles of one or more print heads. Ink-jet devices can print on a wide range of substrates such as paper, plastic, canvas or even doors and floor tiles. Ink-jet printing is used a lot for posters and signage. It is also economical for short run publications such as photo books or small runs of books.

Ink Jet plates A special ink receptive coating is used to print on a metal plate which is then used to print on the substrate, this is the latest development in printing, and as it requires no processing or post baking and can be used immediately therefore reducing cost.

Lower quality than CTP Used For Short run 28

Print Production

In-line inkjet printers are sometimes combined with other types of presses to print variable data, such as the mailing addresses on direct mail pieces.

Laser Printing

Invented at Xerox PARC in the 1970s, laser printers were introduced for the office and then home markets in subsequent years.

Laser printing is an electrostatic digital printing process.

It produces high-quality text and graphics. By repeatedly passing a laser beam back and forth over a negatively charged cylinder called a “drum� to define a differentially charged image.

The drum then selectively collects electrically charged powdered ink (toner), and transfers the image to paper, which is then heated in order to permanently fuse the text and/or imagery.

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Print Production

The drum in particular is a critical component: it must not be left exposed to ambient light for more than a few hours, as light is what causes it to lose its charge and will eventually wear it out

PRE PRESS

Pre Press Prepress operations encompasses the steps during which the idea for a printed image is converted into an image carrier such as a plate, cylinder, or screen.

Prepress operations include compositions typesetting graphic arts photography image assembly and image carrier preparation.

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Print Production

Types of Originals

Line Art - - -

Only black and white pixels Also known as bi level images Line art is sometimes used to describe drawings containing flat colours without tonal variations

Continuous tonal Grey scale or colour image format capable of illustrating continually varying tonal ranges as opposed to line art.

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Print Production

Halftones Halftone is a process by which continuous tone image is simulated by a pattern of dots of varying sizes.

The first truly successful commercial method was patented by Frederic Ives of Philadelphia in 1881.Although he found a way of breaking up the image into dots of varying sizes, he did not make use of a screen, In 1882, the German Georg Meisenbach patented a halftone process in England.

Short while later Ives, improved the process further with the invention and commercial production of quality cross-lined screens

How it Halftone Works?

•

•

•

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Print Production

Halftone will create an optical illusion that makes the tiny halftone dots appears as they are blended into a smooth continuous tone seen by the human eyes The more dots per inch smaller the dots and smoother and more evenly blended the final image appear The lower the LPI the larger and more obvious the halftone dots in the printed image

Halftone

Halftone Screen:

Density:

Densitometer:

Density range:

33

Print Production

A specially prepared glass screen or contact film screen which breaks the different grey tones of the original into a series of different size of dots, which gives illusion of continuous tone

Is the level of Darkness in a negative or positive film or print. The measurement of density is called densitometry.

The optical instrument used to measure the intensity of tone of film or reflection copy as well as the ink reading of the printed copy

The density range is the difference between highest and the lowest density in a photographic image.

What is a screen?

Unlike photography, difference in lightness cannot be directly reproduced in printing.

Printing paper either has colour or nothing at all, meaning there is no such thing as ‘a little colour’/gradation, however screens trick the human eye into thinking that it sees difference in lightness.

In a black and white image, different grey tones can be simulated by printing a number of small dots larger or smaller. These small dots are arranged at regular intervals in a grid structure that is called a screen.

A special glass screen containing a fine mesh structure is used to break a continuous tone image down to dots.

Halftone print becomes a dot while the gird is square because of the diffraction theory

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Print Production

Transparency Light passes through the original and the light then falls on to the sensor

Diffraction: The process by which a beam of light or other system of waves is spread out as a result of passing through a narrow aperture or across an edge, typically accompanied by interference between the wave forms produced.

Halftone Basics

Halftone conversion •

• •

Normal viewing distance The LPI is determined by the viewing distance.

Process of reproduction Type of base material

Screen Ruling

Frequency

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Print Production

•

•

•

Number of lines per inch of screen known as screen ruling.

More the number of lines per inch of screen, the smaller the average dot produced.

The use of finer screen, produced more detail in the picture, than the coarse screen.

For making a positive for halftone the resolution of the image needs to be at 1200DPI

Scren Ruling

Screen Angle: The method of aligning row of halftone dots at different angles to avoid moire pattern, in multi-colour printing, moire pattern is created when overlapping screens create then appearance of unwanted lines and patterns

0°

15°

75°

Moire pattern in halftone Moiré effect is a visual perception that occurs when viewing a set of lines or dots that is superimposed on another set of lines or dots, where the sets differ in relative size, angle, or spacing.

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Print Production

45°

Halftone conversion in Photoshop ImageBit mapHalftone

When the job is printed in single colour the job is printed at 45° Black is also always printed in 45°

Rosette pattern is a moiré pattern in color printing, a very small circle of halftone dots, formed when three or more process color screens are overprinted at the correct screen angles with the proper dot sizes.

Screening technology

AM screening

FM screening-

Staccato 36

Gradation is created thorough the size of the dots.

Also known as conventional halftone screening

Gradation is created through number of dots

It is the most common FM screen used in newspaper the highlight dot measures 42.4 microns which is equivalent to a 2% dot at 85 LPI 3% dot at 100 LPI 4% dot at 125 LPI 6% dot at 150 LPI

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Print Production

Data Loss

At every step in the creation of an image, there is a chance for the image to degrade.

When a photograph is taken, only a small portion of the information in the scene is recorded. When that photograph is scanned, some information is lost too.

A little bit of information is lost in each of the following steps: the creation of the films, the making of the printing plates, and the actual printing of the image.

Dot Gain

Dot Loss

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Print Production

Increase in the number of dots due to loss of information in the mid tones and shadows is called dot gain.

Decrease in the number of dots due to loss of information in the mid tones and highlights is called dot loss.

COlour What is light?

Light Behaviour

Transmission

Surrounding colour

39

Print Production

Visible light spectrum can be broken into three predominant bands of colour.

These bands are red, green and blue and called the primary colours of light

The way that light waves travel depends on the objects they come in contact with, Light waves can be reflected, absorbed or transmitted through an object

How light waves react will be determined by the object they hit. Which colours are reflected, absorbed or transmitted determine the colour of the object

The colour surrounding an object can affect how the actual colour of the object is perceive. If a green circle is surrounded by green, it will appear lighter than if it is surrounded by dark blue

White light (additive colours)

Red green and blue are the primary colour of white light They cannot be produced by the combination of any other colours when they are combined full strength, they will produce white light Colour reproduction on the computer monitor is achieved by combining red, green and blue in varying levels to produce a full colour image

When 2 primary colour are added a secondary colour is created RED + Green = Red + Blue = Blue + Green =

Yellow Magenta Cyan

Additive colour process is used on computer monitor red green and blue lights are combined in varying intensity to produce all the other colours.

A high resolution 24- bit monitor can reproduce 16.3 million colours

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Print Production

Combining Red, Green and Blue – in unequal proportions make new colours, the proportions themselves will determine the colour from three colour, the entire visual spectrum can be created

Subtractive colour

In the printing process we use coloured ink that each reflect two thirds of the visible spectrum. These special inks correspond to the secondary colours of light; namely cyan magenta and yellow By overprinting selected amounts of cyan magenta and yellow the widest range of colours within the limitation of paper and ink can be achieved. In theory, pure CMY pigments should combine to absorb all light and produce black some impurities in the colour prevent it from reflecting all the opposite colour and therefore there is a need for a BLACK

CMYK model Since the objective is to control Red, Green and Blue light.

We print with CMYK. This model is based on the light absorbing quality of ink printed on paper as white light strikes translucent inks certain visible wavelengths are absorbed while others are reflected back to your eyes, thus providing colour to the paper.

Different methods of printing colour on paper Spot colour printing - premix shade of ink Four colour printing - cyan, magenta, yellow and black Hexachrome printing - CMYK+ orange +green 41

Print Production

Spot Colour Premixed readily available inks or designer specifies any shade, the printer can mix the required colour are called spot colour.

GAMUT

A gamut is the range of colours that a colour system can display or print, the spectrum of colours seen by the human eye is wider than the gamut available in any colour model

Among the colour models used in photoshop, L*A*B has the largest gamut

RGB Gamut Contains the subset of Red, Green and blue colours that can be viewed on a computer or television monitor (Which emits red green and blue light) Therefore some colours such as pure cyan or pure yellow cannot be displayed accurately on a monitor.

CMYK Gamut Are smaller, consisting only of colours that can be printed using process colour inks.

Hexachrome Gamut Provides wider gamut, more vibrant greens, oranges, purples and truer skin tones can be achived & also Improve colour range and accuracy

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Print Production

Out of Gamut When colours that cannot be printed are displayed on screen they are referred to as out of gamut colour i.e. outside the CMYK gamut

Process colour The term process colour refers to the use of four specific colourcyan (process blue) Magenta (Process Red), Process yellow and black.

Colour Separation

Prepress changes the original image into four or more films or printing plates. This is called colour separations. Each film or plate represent separate colours. The Four halftones are printed in BCMY register with each other using the colour sequence that they stimulated original full- colour image.

Traditional colour separation Red filter is used to create the plate for Green filter is used to create the plate for Blue filter is used to create the plate for RGB filters are used to create a plate for

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Print Production

Cyan Magenta Yellow Black

Colour COrrectgion

Six major concerns when dealing with colour correcting

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Print Production

1.

The quality of the original image

2.

The quality of the scanned image

3.

Ensuring proper contrast from light to dark

4.

Avoid over exposure

5.

Prevent dot gain which can cause a loss of detail and improper tonal range from light to dark- Gain in dot density in mid tones

6.

Compensating from the printing process, including the paper being utilized

COlour Reproduction

Spot Colours

Duotone

45

Print Production

Special characteristics which aren’t available in process inks such as metallic or fluorescents are avaiable in spot.

Spot colours can reduce the printing cost because it uses one ink and one plate.

When printing a red and black letterhead in process inks, you will actually need three inks: magenta, yellow and black.

Spot colours are not effective when printing a full colour piece, however, because adding a spot color means that an additional plate needs to be added to the printing process, which will significantly increase the cost of printing.

Duotone is a halftone reproduction of an image using the superimposition of one contrasting colour halftone over another color halftone. This is most often used to bring out middle tones and highlights of an image. The most commonly implemented colours are blue, yellow, brown, and red. The image achives more depth, but is still inexpensive as its made from 2 colours.

Hexachrome

Fourcolour

46

Print Production

Hexachrome is a high-fidelity 6-color printing process which uses enhanced CMYK inks along with an orange and green. This system provides a wider gamut. Standard CMYK inks appear dirty when compared to the more vibrant Hexachrome cmyk.

The four-colour process is used to produce a complete range of colours. In this process, the material to be reproduced is separated CMY plus black, which is used for density and image contrast.

Planning and Design

Factors to consider before starting a print job

Trim size

Software

Paper limitations

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Print Production

Print size of the finished sheet allow the best useof the signature sheet a small change in only one dimension can save a lot of wasted paper.

Is the artwork provided compatible with the printers software and the verison used by the printer.

Some light weight and vert heavy stock may give you problems also some paper come in certain size only and will have to be cut down

Paper & printing

Dummy print

Ink units

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Print Production

knowledge of the material in use is important to set the correct halftone screen, image resolution (1.5-2 times the halftone screen), and dot gain for photographs

Make a dummy to make certain you have is of the correct amount of pages signature consist of 48 and 16 pages in most cases

Some light weight and vert heavy stock may give you problems also some paper come in certain size only and will have to be cut down

Data Input Scanner: CCD based flatbed scanners are most versatile and popular image capturing devices for dtp and professional press.

Drum scanner • • •

•

•

Use a technology called a photomultiplier tube (PMT) Capable of registering a wide density range Its manufacturing and maintenance cost is higher than CCD devices Require the knowledge and practice of an export to produce the best settings Only supports flexible originals.

Flatbed flatbed scanner can produce acceptable results, if not very good colour reproduction, depending on your requirements, however, a drum scanner is still the best tool to use, to create the highest quality scanned image from film originals •

•

•

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Lesser density range- The CCD will not “see” all the shadow detail in contrast transparencies not reproduced these areas fully.

Scanning resolution is around 5500 DPI for true optical resolution A spec of dust lying on a CCD sensor may cause streaks across the image on the scan direction

Print Production

CCD containing grids of pixels are used in digital cameras optical scanners and video cameras as light sensing devices.

dESKTOP pUBLISHING

Caliberation

Colour profiles

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Print Production

The simplest calibration methods involve adjustments to the contrast and brightness settings of your monitor. Commonly done with device that change color frequently like monitors and printers.

An intermediate method uses special software to calibrate your printer, scanner and other devices so that what you see on-screen, what you scan and what you print all look the same.

The profile is a colour space that was previously measured and a set of instructions for the gamut mapping that is to be carried out.

There are different types of profiles.

Device dependent profiles such as printer, scanner, monitor profile. They each describe the colour space that the device can represent.

raster v/s Vector

Raster graphics

Vector graphics

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Print Production

In computer graphics, a raster graphics image is a dot matrix data structure, representing a generally rectangular grid of pixels, or points of color, viewable via a monitor, paper, or other display medium.

Raster images are stored in image files with varying formats

Vector graphics is the use of polygons to represent images in computer graphics.

Vector graphics are based on vectors, which lead through locations called control points or nodes. Each of these points has a definite position on the x- and y-axes of the work plane and determines the direction of the path; further, each path may be assigned various attributes, including such values as stroke color, shape, curve, thickness, and fill.

File formats

JPEG

TIFF

EPS

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Print Production

Joint Photographic Expert Group is a commonly used method of lossy compression for digital images, particularly for those images produced by digital photography Ideal for quick preview

Tagged Image File Format is a a popular format for high color-depth images. The ability to store image data in a lossless format makes a TIFF file a useful image archive, because, unlike standard JPEG files, a TIFF file using lossless compression (or none) may be edited and re-saved without losing image Ideal for Lossless compression

Encapsulated PostScript EPS files are more-or-less self-contained, reasonably predictable PostScript documents that describe an image or drawing and can be placed within another PostScript document.

Ideal for image links

PDF

GIF

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Print Production

Portable Document Format is a file format used to present documents in a manner independent of application software, hardware, and operating systems. Each PDF file encapsulates a complete description of a fixed-layout flat document, including the text, fonts, graphics, and other information needed to display it.

Ideal for printing

Graphics Interchange Format allows upto 256 colours, and allows for moving images.

Ideal for web based short videos

Check list for Layout

1)

Set the correct paper size.

2)

Set the trimming parameters to size

3) Do not select font modifications in the

application program (artificial italics or bold)

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Print Production

4)

Use images in the right resolution (scan correctly or reduce the resolution in the image editing program)

5)

Avoid hairlines

6)

Observe minimum and maximum tonal values (E.G. screen tonal values between 5 and 95%)

7)

Remove superfluous objects

8)

Remove empty pages

Colour separation

Is the process of splitting an image into the printing primary colours CMYK. Traditionally an image was photographed four times with a RGB filters attached to the lens These negatives would be used to develop a halftone positive to be used for making printing plate. Now the same process can be done digitally and is refered to as electronic seperation

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Print Production

POST PRODUCTION

Post Press Post-Presms primary involves the assembly of printed materials and consist of binding and finishing operations

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Print Production

PAPER PAPER

Paper was invented in china in the 2nd AD and was first used for writing in Egypt, and since then has been an indispencible part of visual communication The goal with choosing paper is to select the paper type and grade that will achieve your goal at the lowest cost.

The first step, therefore is to establish the goal of the piece.

Think about what the piece will be used for and in what situation.

Paper comes in 3 categories 1.

2.

3.

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Coated:- These paper have a coating applied, Uncoated: No coating looks flat, almost all coloured paper is uncoated Matte: Thin Coating applied which is not buffed to a shine

Print Production

Types of paper

Uncoated:

Matte:

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Print Production

Inexpensive, no glare, easy to read, easy to write on, pen ink wont smear sell sheets. used for some brochures. flyers, pieces which will be written on newsletter, inexpensive four colour pieces

Moderate cost, no glare, photos look fairly good, pen ink smears a little, has a tendency to mark on areas of heavy solids Newsletter, stationary etc has a tendency to fade

Dull:

Gloss:

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Print Production

No Glare, sophisticated look, smoother, surface than matte so photos look better, pen ink smears a little has a tendency to mark on areas of heavy solids, used for higher end brochures four-colour pieces

Photos look very good surface glare so it’s not as easy to read pen ink will smear Catalogue covers and interiors brochures sell sheets, portfolios. postcards

Newsprint:

Tracing paper

Map litho

Mirror coat

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Print Production

Its a thin and light paper, generally of 80gsm and has distinct brittle texture to it. The lineing causes the paper to rapidly become brittle and yellow when exposed to air and sunlight

Is translucent and resistant to oil grease and to a large extent.

Top surface is smoother, used for books leaflet etc.

Art paper coated with china clay mirror finish

Offset paper

Duplex board

Art paper

Cartridge paper

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Print Production

Rough on both side, more rag content, good for folding.

Boxboards, used in cartons

China clay coating covers pours surface, gives smooth finish, less absorption of ink, gives good ink depth can be matte or gloss finish

A thick white paper with stiff feel more rag content, preserved for long time, used in sketchbook, certificates, stamp paper.

Cards

Ink-jet paper

Photos paper:

Grey board lined or unlined

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Print Production

Thicker paper are called cards. Sold ion gross= 144 sheets

Is paper designed for ink-jet printers typically classified bu its weight brightness and smoothness by its opacity

is a category of ink-jet paper designed specifically for reproduction of photographs. Photo paper is usually divided into glossy, semi matte or silk and matte finishes.

Grey board made form waste paper. It has a rough texture good bulk and is grey in colour. Used for packaging material or covers for publications.

Recycled paper.

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Print Production

Is made from waste paper, usually mixed with fresh wood pulp.

If the paper contains ink it must be delinked, this also removes fillers, clays and fibre fragments

Size There are many page sizes that have existed, at different times and in different countries, for example the local standard used in North America include letter, legal ledger) the paper size affect writing paper, stationary, cards and some printed documents. The standard also have related size for envelops. to avoid confusion an international standard has been introduced • • •

A0= 841 by 1189 mm C0= 917 by 1297 mm B0= 1000 by 1414 mm

The paper comes in 2 standards 1. British 2. International In India we follow the British standard.

Grammage This standard defines grammage as grammes per square meter thus the weight of a single sheet of A0 paper defines the grammage of that paper type as the A0 size is defined by ISO 216 as having an area of 1 Square meter. An A0 sheet of 80GSM paper will weigh 80 gsm, an A0 sheet of 100 gsm paper will weigh 100 grams.

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Print Production

When smaller side of the paper is multiplied by two you get double the size of the respective size

GSM: Gram per square meter, the weight of the paper in countries that use ISO paper sizes is defined by iso paper size is defiends

by ISO 536 Paper and boarddetermination of grammage.

13mm gripper on the bottom 10mm margin 3 sides 5mm space on each side of a book to allow for cutting

A Sizes

The starting point is an A0 sheet with an area of one square meter folding A0 sheet on half results in an A1 sheet folding an A1 in half on the longer end gives you an A2 sheet and so on.

The height and width are in the ratio of 1 to the square root of 2.

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Print Production

B Sizes

The B range is covers an immediate need of special applications such as oversize documents and posters

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Print Production

c Sizes

C series is used for folders post cards and envelops and A4 size sheet will fit into a C4 envelope and A6 will fit into C6

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Print Production

Ink WHat is Ink?

Ink is a liquid or paste that contains pigments or dyes and is used to color a surface to produce an image, text, or design

Ink ingredients

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Pigment:

Ingredients responsible for the color

Vehicle

Liquid portion of the ink.

Purpose

Is to carry the pigment to the substrate

Print Production

Ink characteristics Body Consistency

Tack

Resistance

Splitting

Permanency

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Print Production

On prolonged exposure to air and the increase in heat produced by the roller, the consistency may vary from time to time.

Stickiness of the ink.

Resistance of the ink film to split

Splitting occurs when the ink from printing plate is transferred to the printing blanket

The degree in which printed ink resists the fading power of light.

Viscosity

Length

Tinting strength

Opacity

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Print Production

Degree that ink resists the flow even under force. Viscosity also can change with the frictional and heat generated by the roller train

Ability of the ink to flow.

Necessary for the ink to move properly through the roller train of the press to achieve best results.

Ability of the ink to produce a tint with addition of white pigment

Covering power of the ink.

Differenrt pigments have different degrees of opacity beacuse of the substances used ti ptodue the pigments

Ink related problems

Setoff

Ink adhesion

Mottling

Crystallisation

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Print Production

The transfer of ink from sheet to back of the next sheet. Caused by too much ink being applied or slow drying.

Result of set-off and slow drying ink, which in turn usually the result of poorly adjusted press settings.

Uneven appearance in the solid area of the printed document caused by uneven distribution of ink, non absorbent papers or faulty press adjustments.

Time between each color printing is more and if ink dry, it will not accept the next color.

Binding Book binding is the process of physically assembling a book from a number of folded or unfolded sheets of paper or other material

Binding

Library

SOft cover HArd cover Quater Binding

Half COver

Full cover

Flat Back

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Print Production

Round back

Binding

Stationary loose Leaf Wiro

Spiral

Wire Center Staple

Side Staple

PAd

Cut board

Office

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Print Production

Comb

Imposition The arrangement of pages on the press sheet so that when folded the pages read consecutively. How you arrange the pages on the sheet and the pages, and how the job will befolded and bound.

Factors to consider

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Print Production

1.

The design of the printed piece

•

•

•

•

Whether it is multicolour, process colour or single colour Whether one or both sides of the sheet are to be printed Whether one or several duplicate images are to be reproduced The type of finishing operations that are required such as folding, trimming and binding

2.

The type and size of the press to be used

•

Whether the press is sheet fed or web fed and if the job is ganged, the size of the press sheet, and whether to use a large sheet or a single unit

3.

The type of paper to be used during printing

•

Whether image position in relation to grain direction will affect folding operation

Types of imposition

One side imposition

Sheet wise imposition

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Print Production

The simplest form of imposition is one side imposition. In one side imposition, one printing plate is used to print on one side of the sheet as it passes through the printing press. The type of imposition is common in small, offset press operations.

Two printing plates are used in sheet wise imposition. One printing plate is used to print on one side of a press sheet.

A second plate containing different information is then made, the sheets are turned over and the sheets are printed on the other side from the second plate.

Sheetwise layout

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Sheet wise layout, need two separate plates for each colour, one for each side of the press sheet. This illustration shows an example of the front and back plates used to print the press sheet, and how the pages match after both sides are printed.

Print Production

Ganged imposition

Often the job to be printed is smaller than the press can handle, or it is so much smaller than the standard press sheet size that printing only that one job on each press sheet would be a very in efficient use of equipment. When a press sheet carries only one job it is called one up imposition When more than one job is run on the same sheet it is called two up. Three up, four up and so on‌ It makes no difference if the same or different images are printed, the same terms are used

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Print Production

Work and turn Different machines use different configerations of switching the plates during print, it is important to know which type the chosen printer is going to use in order to set the page margins, and page sorting accordingly.

Work and turn Work and tumble will require more margins as provision for the gipper needs to be made on both top and bottom of the sheet.

Work and turn will require plates to be spread in such a manner that 1 is behind plate 2 so that it can print behind the impression left by plate 3.

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Print Production

Work and tumble

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