s e g a 16knpowle-dhgoew of
ow n k nd
a
ideas.indd 1-2
23/11/2009 14:31:08
//6 5 A N TIV 7 PA INT ING E C NT RO O D O PRI A D LO NE UC Index. T U N O IN T CU R P AN ION P P D R PRI RA RO 4-5 ANMINTRODUCTION I INTO BASIC COLOUR N O S E T C N C SPACES 6-7 PANTONE AND SPOT P NT CTI COLOURS O E T O E B S 8-10 CREATIVE COLOUR S FIN CEPROCESSES SES11 FOR SE T C ISH //1 //12-13 PR S / OL / PROCESSES 14-15 FEATURE: 6 EPRINT 1 I 4-1 16-17NT 10-1 SLITHOGRAPHY-1IN7 PRACTICE 5 F //12 1 18 WHATW SUBSTRATE? HAT EAT -13 U S R s e g pa ge
16knowle-dhow of
ow
kn and
Print. An Introduction
//
//
//
// HELP I’M PREPARING AN OVERVIEW: COLOUR FOR PRINT // // // PRINT FINISHES //
Print. An Introduction 03
ideas.indd 3-4
23/11/2009 14:31:08
CMYK vs RGB The two most common colour spaces found on a computer are RGB & CMYK. But why do we need them and what is the difference? The RGB colour gamut can reproduce 70% of the colours that can be seen with the human eye. The RGB palette is made up of red, green and blue light and is known as an additive colour space. Everything from monitors to digital cameras use an RGB colour space, as the gamut is wider than a CMYK colour space. This means the images we see on screen are made up of a wider spectrum of colours and produce a more saturated image due to the intensity of the colours. RGB is primarily used for web based graphics. CMYK is a subtractive colour space used by mixing Cyan, Magenta, Yellow and Key (Black) colours. This colour system is used solely for print and its gamut is much smaller than RGB. The restrictive gamut means a smaller number of colours can be printed. There are ways in which we can print specific colours outside the CMYK gamut known as Pantone速 and Spot colours (page 6-7). By mixing all 4 process colours together we can make a deep black, known as registration black, which is used predominantly for registration marks. It is important to know which colour space we are working in if working for print or web. For example if we were to produced a document for print using an RGB colour space, then the colours within the document that were outside the CMYK gamut would be converted to the nearest colour within the CMYK colour space.
CMYK is a subtractive colour space used by mixing Cyan, Magenta, Yellow and Key (Black) colours. 04 Print. An Introduction
ideas.indd 5-6
Print. An Introduction 05
23/11/2009 14:31:13
PANTONES & SPOT COLOURS Pantone and Spot colours are commonly used by graphic designers to ensure that a certain colour will print accurately if it falls outside the CMYK four colour process colour gamut. A spot colour is any colour generated by an ink, which is either pure or mixed from other inks. Special colours such as these require a
06 Print. An Introduction
ideas.indd 7-8
specific colour mix and are often used if a vibrant colour is required. Pantone colour swatch books feature all the colours in the pantone range. These colours can sometimes be matched accurately to a process colour. However, if a colour is critical, for example in a corporate identity, then a spot colour ink chosen from the pantone sample book can be chosen.
Each pantone colour has a reference number which is recognised by software such as the Adobe Creative Suite.
Pantone colours are supplied in solid, pastel and
metallic colours amongst others. The type of colour selected depends entirely on the substrate (16-17) the designer is printing onto. This is because different substrates can make the same colour appear differently. Pantone swatch books are a must have for any graphic designer working for print. The cost is high and they are usually replaced annually. The reason for this is that exposure to sun light can
fade the colours and not give a true freshly printed representation. There is a huge variety of reference books to buy but the ones we can work with day to day include swatch books for Pantone Coated, Uncoated, Solid Coated, Solid Uncoated, Solid Matte. Pantone also produce swatch books for metallic inks and pastel colours.
Print. An Introduction 07
23/11/2009 14:31:27
CREATIVE COLOUR PROCESSES
OVERPRINTING IS A BASIC FUNCTION THAT CAN ADD AN INTERESTING GRAPHIC EFFECT
Overprinting is a option available to designers that allows us to overlay two colours to make another without using another ink in the process. The best overprinting examples are usually done with typography as they use solid colours. As the graphics are layered upon one another the colour will change depending on the colours that are overlaid. Overprinting in graphic design for print is common on posters. By default objects and type that overlay one another usually ‘knockout’, i.e. the colour printed on the layer above will always printed instead of the colour below it. Design programs such as Illustrator and InDesign have overprint functions, and software such as Photoshop can achieve a similar effect by using blending modes. Overprinting onto black would not make any noticeable difference to the black colour. Although, when the other 3 process colours are overprinted onto black, the black becomes stronger colour. Overprinting using images, vector graphics and gradients can also be achieved with good results.
08 Print. An Introduction
ideas.indd 9-10
CREATIVE COLOUR PROCESSES 100% Cyan
90%
80%
70%
60%
50%
40%
30%
20%
10%
Tints are a good way to keep print costs within a tight budget without losing visual integrity. Colours can be used creatively to make a 1 colour print seem more complex through the use of colour tints. We can make tints from any pantone colour as well as process colours Cyan, Magenta, Yellow and Black when used in isolation. For example the diagram shows a 100% Cyan ink which has a 10% reduction which makes that 90% Cyan. The next box down is then 80% cyan, and so on until it reaches 10%. I would not make any more percentage reductions after this point as the colour becomes too opaque. We can repeat this for any single colour ink.
0%
Print. An Introduction 09
23/11/2009 14:31:27
Monotone & Duotone A good feature of using a duo toned image exported from Adobe Photoshop to Adobe InDesign is that the colours you use for the image gets directly transferred to your colour swatch library ready for use with shapes, and typography.
Monotone
Duotone
Full Colour
We can use other creative colour processes such as Mono tones, and Duo tones to change the look and feel of an image, and this can be handy to use if we have a set colour palette to work with. For instance, if we are to produce a poster with just two colours like Pantone references 222c and 299c then we could also produced imagery that only uses these two inks. I have added the light blue to the highlights in the image and the burgundy red to the shadows of the image. By using only two colours this means that the print job would be cheaper than using a full 4-colour process. Here are examples of a full colour image as well as Mono tone and duo tones. Effectively, overprinting (pg11) two different colour mono tones would create a duo tone print. We can also create Tri tones and even Quad tone prints. We can also create selective duotones by manually selecting parts of an image using spot channels to colourise that part of the image. A good feature of using a duo toned image exported from Adobe Photoshop to Adobe InDesign is that the colours you use for the image gets directly transferred to your colour swatch library ready for use with shapes, and typography.
10 Print. An Introduction
ideas.indd 11-12
Help! I’m
preparing colour for
print s che tcht a a d Sw r sw
orte
u om colo r ted fr r p y n m o I ure a imp he not Ens at you m to a ue. h es t prog ra me val y one the sa that an hold e sure coated r inted p Maktone un to be . e k n r c pa urs a d sto e o t l co ncoa on u
Regis t
Ensur ration, no t blac regist e all you to k ration p r i n t regist i , n i s in r oppos ation. This ite of is the but re t gistra he last poin a muc tion p t h r using r icher bla ints as but us ordinar y bl ck than a proce es all four ck ink ss col ours.
can Pre-press tips that al help you avoid cr uci and costly mistakesork when sending artw to a printer.
rs d colou e s u n u all swatch Delete in your o
s if lour o c ot . e sp ed too rs are s u t u e ’ e o n n l Do don’t pot co u do us e n o s i u y l f yo ure al for. If his is ith
Ens unted olour, t work w t o o acc ecial c end ar t rs. Sp to u p s d o e ol a s don’t s sign ot c but sed sp be as r nishe n a . u a v s e un urs c spot nish colo r int as r int fi nter i p be p other the pr e d r an e su his. Mak ws of t kno
es imag es are t r e v g a Con ll im B to
ond t lours The co ould cor resp h e panel s ment you ar rking u o c o w d n e e th on. Wh r int job g n i k r rp wo o colou urs, for on a tw g 2 spot colo at the in th , and us , make sure e e Cyan c instan he colours lik ey are K t rest of a, Yellow and t Magen from the deleted panel. swatch
RG re a Ensu r ted from s can conve as colour ly to how t CMYKr differen creen. a e n p o s ap oked that were o l y e ay s th olour een m The c ate on scr mut and accur e out of ga uted for t now b be substi colour. t d woul xt neares e the n
Black, not registration Ensure all you want to print is in black and not registration. For instance if you are preparing artwork that is a solely black, you will need to make sure the artwork is in black only. Sending artwork that is filled with registration will utilize the full four colour process.
Print. An Introduction 11
23/11/2009 14:31:51
The plates can either be etched using a laser or hardened using UV light. The latter technique lasts much longer than the laser etched plates, so would be more costs effective for large print runs.
An Overview:
PRINT PROCESSES The four main industry standard print processes are known as Rotary Printing, which includes Offset Lithography (pg 14-15), Flexography and Rotogravure, Digital Printing, which is prints digitally which prints in a similar way to your printer at home, Screen Printing, which uses screens to print from by layering inks and is often used for t-shirts and generally anything that is difficult to print digitally, and Pad Printing, which takes ink from a plate and transfers it to a pad, which then can be transferred to a variety of substrates either 2 or 3D. All the four processes are set up to print differently and better suited to particular jobs. For example if you were to print limited edition run of posters on a thick stock, you may decide to print using screen-printing. Screen-printing is suited to limited print runs but can produce a better quality than digital printing. Screen Printing Screen printing is a print process which consists of ink being forced through a screen, traditionally made from silk. Today, the screens are usually made from a synthetic fabric, which is more cost effective and longer lasting. The screens are coated a photo emulsion, which hardens when subjected to UV light. Setting up printing screens can be costly so it is not cost effective to produce a screen for a one-off print job. A new screen has to be produced for each ink colour you decide to use and the design you are printing will have to be transferred to the screen by exposing it to UV light for a number of seconds. For example, if you were to print a full colour image, you would need to separate the colours into cyan, magenta, yellow, and key channels digitally using graphic design software such as Adobe Photoshop and then printing the four colour separations separately onto acetate sheets ready for exposure. These are printed in grayscale because they only act as a stencil for your final design.
12 Print. An Introduction
ideas.indd 13-14
The screen is exposed and where light cannot penetrate through the stencil the emulsion does not harden like the rest of the screen. After this process, the screen is washed and the emulsion that has not hardened falls away to reveal your artwork on the screens ready for printing. Digital Printing Digital printing is more familiar to us as we take advantage of it everyone day if we ever want to print anything from a computer. Professional Digital printing works in the same as our printers, just on a much bigger scale. Digital printing can be a cost effective way to print a one off, and can also be used to print large scale banners. Most large format digital printers can print up to A0, which is twice the size of A1. Canvas and PVC banners are usually printed digitally due to them being produced in 1’s and the fact digital printing allows us to print them in any length. Pad Printing Pad printing is a printing process that can transfer a 2-D image onto a 3-D object. This is accomplished using an indirect offset gravure printing process that involves an image being transferred from the printing plate via a silicone rubber pad onto a substrate (surface to be printed). Pad printing is used for printing on otherwise impossible products in many industries including electronics, appliances, sports equipment and toys.
“DIGITAL PRINTING CAN BE A COST EFFECTIVE WAY TO PRINT A ONE OFF.”
Rotary Printing Rotary printing is common in the world of newspaper and magazine printing and has three main types all of which suit one print job better than another. The principle of rotary printing is nothing new but more viscous inks and improvements in technology means a better quality of print, better accuracy and faster production means it will be used for many years to come. Two large cylinders known as the impression roll and the gravure cylinder turn in unison to allow the paper to glide through. The gravure cylinder will be partially submerged in a large inkwell. This drum will apply the image to the substrate via the plate that is wrapped around it with the artwork etched onto the surface. The materials used to make the plate depend on the printing process being used. Rotogravure is a common commercial relief printing process in which an image is engraved into a copper printing plate (that’s why the plates are so durable) and is pressed directly against the substrate. Small cells are engraved into the plate that holds the ink ready to be transferred to the stock. It is a high speed print process that delivers a high volume of production and has the widest print presses. It is used for substantial print runs, such as newspapers and magazines. Flexography is printed using the surface differences in the plate. The process creates a rubber relief of the image, which is inked and pressed against the substrate. It was developed for printing packaging and traditionally gave poor results but now it competes with the likes of rotogravure and lithography, particularly as it can print a wide range of substrates due to the flexibility of the plate. It is often used for medium to large sized print runs. This print process is used for printing onto 3D objects such as soft drink cans and food packaging. Rotogravure and flexography print processes uses lower viscosity inks than lithography so the drying time is much faster.
Print. An Introduction 13
23/11/2009 14:31:55
Feature
Lithography in practice.
Invented in 1796, Lithography has grown with the times from using fat and oil to now where the image is made of polymer that is applied to anodized aluminium plates. Lithography is the most versatile print process and the most commonly used for short to medium print runs.
fed presses would be used for newspapers, magazines and reports because of the high volume.
It produces good photographic reproduction and fine linework. It works by taking an inked image from a printing plate and then transferring or offsetting it on to a rubber blanket roller. This is then pressed against the stock or substrate.
Today, it is not uncommon for a printer to have a lithographic press that can handle five or six inks. This is so the designer can use all four process colours, and a spot colour or spot varnish. This means that the paper will only have to pass through the press once. Without the extra handling a full colour print plus spot colour would have to be passed twice, once for the process, and then the print bed has to be cleaned before the spot colour is loaded into the press for the second pass.
Lithographic plates are smooth and works on the basis that oil repels water. When the plate passes under the ink roller, non-image areas that have a water film repel the inks which stick to image areas.
“
Web-fed documents such as Magazines and newspapers are suited to the Lithographic process due to it’s great speed of production and how quickly the ink dries.
�
14 Print. An Introduction
ideas.indd 15-16
Lithography is considered to be the most commonly used process because plates are easy to prepare and the cost of printing is relatively low. Lithography printers can either be sheet fed or have a continuous web feed. A Sheet-fed method would be used for a small print jobs including flyers and brochures, where as web-
Plate making The plate is exposed using a light sensitive coating combined with a reversed image in which it is developed for a set amount of time. Once this time has passed the plate is checked and should be readable and the image area is ready to be coated with a chemical attracts ink and repels water. The non-image area is coated with a chemical that achieves the opposite effect.
Wetting The prepared plate is attached to a giant cylinder. When the press starts and the cylinder rotates, it first comes into contact with the water rollers. The water flows over the cylinder and the parts of the image on the plate that were previously treated are called into action.
Inking
A short run of leaflets can be printed using offset lithography ready for trimming and folding.
Next, the ink roller applies oil based ink to the plate. The complex system ensures that the ink is distributed onto the plate thin and evenly. The
non-image areas of the plate now repel the ink that is applied to them.
Offsetting The final roller is a rubber blanket, which is pressed against the printing plate and carries away a reversed inked image. The rubber blanket has flexibility so it makes an impression on various types of substrate during the printing stage. The impression cylinder constantly re-inks the rubber blanket so that each print is a good as the last.
Printing In the last step, the sheets, either individually (sheet-fed) or on a continuous roll (webfed), are passed through between the impression cylinder and the rubber blanket. The inked blanket, which holds the negative image, and then creates a positive impression on the substrate.
Print. An Introduction 15
23/11/2009 14:32:01
Print Finishes Print finishes can add a special touch to your printed artwork whether it is through the use of foil blocking, spot varnishes, die cutting, binding, and embossing among others. Although the application of print finishes signals the end of the production process, these techniques should not be considered an afterthought. They are an integral part of the design at a planning stage. Foil blocking Foil blocking or foil stamping as it is sometimes known, is a process by which a coloured foil is heat pressed onto a substrate via a heated die. Foil blocking can add to a finish’s desirability particularly if it contrasts well with the colour of the document. For example a metallic silver foil blocking usually works rather well on a solid black finish. The process is versatile and can be used for typographic areas and can be used in conjunction with embossing to add a professional and high quality feel to a heavier card stock like a book cover.
16 Print. An Introduction
ideas.indd 17-18
“varieties (of spot varnish) include gloss, matt, pearlescent, textured, neutral and UV varnish.”
spot
varnish Spot varnishes can be applied in the same way that ink is applied to a stock. They come in various forms depending on the substrate they are to be printed on. The varieties include gloss, matt, pearlescent, textured, neutral and UV varnish among others. They are used to give a glossy finish to a certain area and often work well when applied to typography to make it stand out against an uncoated stock. They can also be applied to images because they make the colours appear more vivid, and in turn appear much more saturated and sharper. Spot varnishes, in some cases, can also be used in place of an ink. For example if you were to have a completely solid black finish on an uncoated stock, you could apply a spot varnish instead of a colour to typography and the shine of the varnish would make the typography stand out when light was reflected off the front of it.
Print. An Introduction 17
23/11/2009 14:32:02
A higher quality bond stock can be used for letterheads.
What Substrate?
The weight of the paper stock you select also comes into question depending on the printed materials end function. The universal system for measuring how thick the stock is GSM (Grams per square metre) gives us a indication of the weight of the paper. The higher the GSM value the weightier the stock will be. Choosing the correct GSM to fit the purpose and the budget can be tricky at first. If you were to produce a leaflet on a fairly small budget, for example, you would have to select a paper that was opaque enough to be duplex printed without holograms appearing on either side, however, it also has to be flexible enough to fold.
Paper characteristics that affect printability include its smoothness, absorbency, opacity, and ink holdout. The substrate we use can affect how our work is viewed. For example, if we were to design a flyer or brochure discussing organic produced, we would look to use a natural stock that had not been chemically treated like the usual printing papers we can buy.
18 Print. An Introduction
ideas.indd 19-20
The substrate would probably remain uncoated as well. Uncoated stocks generally absorb the ink much better than coated stocks. There are other finishes to chose from such as wove, which has a uniform surface made by a woven wire roller that presses the paper. Woven substrates are coated and are suited to stationery and book publishing. Laid paper is a premium quality paper with a textured pattern of parallel lines similar to hand-made paper and is suited to business stationery. Bond stock is an economic uncoated wove paper often used for copying and laser printers.
This publication was printed on two passes (a total of four due to the duplex), once for the process colours and once for the spot colours 222C, and 299C. The interior is duplex printed on 130 g/m² art paper and the cover is duplex printed on 300 g/m² art paper with lamination. The publication was saddle stitched due to the low number of pages.
Eles E R F samp
Stock is a major factor and can make or break a piece of printed design. In short, you as the designer, should always try to make your artwork look as good as it possibly can whilst keep the cost under budget as much as possible. There are many varieties of paper stock but two main ones are coated and uncoated stocks. One of the first decisions a designer has to make is whether to print onto a coated or uncoated paper depending on the budget.
This publication was printed using the full colour process and three spot colours. The spot colours could have been converted to process colours but with a noticable difference.
k stoc inside. er p al pa
l loc a ful you tact urer for n o t C ufac book man sample
Selecting coated or uncoated papers may be decided upon whether your artwork is full of colour. Folding a coated paper with a solid colour may crack and be unsightly where as using an uncoated paper may not work because it could be distributed in a place where it could become wet or dirty. There are many, many more types of substrate we can print depending on the print process we decide to use from recycled paper stock to wood free paper stock.
Print. An Introduction 17
23/11/2009 14:32:06
custom pouch for stock samples, to be stuck to page above as shown
Eles E R F samp
k stoc inside.
aper cal p full o l u a yo r for tact Con facture ook u b man sample
ideas.indd 21-22
23/11/2009 14:32:06