The Print Process Leigh Wortley
Contents CMYK & RGB
4
Offset Lithography
14
Gamut
5
Rotogravure
15
Pantone & Spot Colours
6
Flexography
16
Pantone Guides
7
Pad Printing
17
Grey Scale
8
Specialty Printing
18
Half Tone
9
Laminates & Varnishes 19
Mono Tone
10
Bibliography
Duo Tone
11
Digital Printing
12
Screen Printing
13
20
CMYK RGB CMYK refers to the four inks used in most color printing: cyan, magenta, yellow, and key black.
Though it varies by print house, press operator, press manufacturer and press run, ink is typically applied in the order of the abbreviation. The “K� in CMYK stands for key since in four-color printing cyan, magenta, and yellow printing plates are carefully keyed or aligned with the key of the black key plate.
We see in three primary colours: red, blue and green. This is what we seen on screen i.e computers, televisions ect. Printers, whether they be commercial or for home use cannot print in RGB and so CMYK is used instead. A CMYK printer must compete with the many shades of RGB with only one shade each of CMY which it will mix using different optical techniques.
Gamut Gamuts are used by designers and printers to calculate the range of colours that can be produced with a given set of colourants on a particular device or system. Colour printing systems cannot reproduce the full spectral colour gamut that the human eye can see. An RGB gamut can produce about 70 percent of these colours while the CMYK produces far less. “Out of gamut� refers to
a range of colours than CMYK can not reproduce.
Pantone & Spot Colours Spot colours are used to ensure that a particular colour in a design will print. This may be necessary is out side the range of gamut or because it is a specific logo e.g a corporate logo. Special colours have a greater intensity and vibrancy as they print as a solid colour rather than one that is composed of half tine dots.
Pantone Guides Pantone Solid: A range of solid metallic, pastel and process colours that can be used on different paper stocks. Pantone Pastels: A range flat, solid by very pale colours. These are different to tints as they print as a solid colour without visible dots. They are available in both coated and uncoated swatches. Pantone Hexachrome: A range of six process colours used for hexacrhome printing. In addition to CMYK process colours, the system adds green and orange process colours allowing it to reproduce 90 per cent of the pantone PMS colours. Pantone Metalics: A range of over 300 special colours that give a metallic effect including silver, gold and copper.
Grey Scale Half Tone Grey Scale -
Saturated of all Colour and can be used as a mono or duo tone.
Half Tone -
Uses black and white or CMYK dots. When combined together, they fool the eye into seeing a continuoustoned image.
Mono tone Duo Tone Mono Tone -
Duo Tone -
Uses a single colour + tints. Very cost 2 colours can use more tints and is affective as it only needs to use one also just as cost affective as mono tone. coloured ink.
Digital Printing Digital printing is the reproduction of digital images on a physical surface. It is generally used for short print runs, and for the customization of print media.
for registration and position.
- Every print can be different, because printing plates are not required, as in traditional methods.
This is the most popular type of print process as anybody can have a digital printer in their house. Print proofs are not required and unlike most print processes, the ink sits on the surface of the paper and dries there and there is far less wastage.
- There is less wasted chemical and paper, because there is no need to bring the image “up to colour� and check
- Because there is less setup, it is useful for rapid prototyping, and cost effective for small print runs.
Screen Printing A screen is made of a piece of porous, finely woven fabric called mesh which is stretched over a frame of aluminium or wood.
Originally human hair was woven into screen mesh but these days mesh is made out of man-made materials such as steel, nylon, and polyester. Areas of the screen are blocked off with a non-permeable material to form a stencil. A negative of the image
is made so that the ink will go where there is no image space. For example, All white spaces will be filled with black to form a reverse image. The screen is then placed atop paper or fabric. Ink is placed on top of the screen and a bar/piece of wood is used to spread the ink across the mesh and the design.
Offset Lithography Offset litho uses etched aluminium plates wrapped around a cylinder which then transfers ink onto a rubber ‘blanket’ cylinder and from there onto the paper/plastic/fabric ect. This process can either be sheet fed or web fed, web being huge rolls of paper used for very large print runs. This process uses CMYK colour process and has a different part of the machine for each colour separation, therefore an
image is printed using four different etched aluminium sheets.
Rotogravure The images are etched onto copper sheets instead of aluminium like offset litho and then wrapped around a cylinder. It works upside down in comparison to offset litho, with the impression cylinder on the top instead of the bottom. There is also one less cylinder involved, cutting out the ‘blanket’ cylinder all together. Because this cylinder is missing, the image etched onto the copper plate is a mirror image to ensure
that it prints the right way up on the paper/ plastic/fabric. The vast majority of rotogravure printers are web fed, and the few sheet fed ones that exist are classed as a ‘speciality market’. One example of roto printing would be newspapers. Rotogravure presses are the fastest printing process and can print onto very wide substraits, such as vinyl flooring.
Flexography This print process is used for printing things that are generally quite difficult to print on, such as foils and plastics, mostly food packaging. A rubber sheet is made using a mirror image and then wrapped around a cylinder where is prints ink directly onto the substrait. A flexography press has it’s advantages over other rotary printing methods as a wider range of inks can be used with it.
Pad Printing “Pad printing is a process that can transfer a 2-D image onto a 3-D object� This process is used for printing onto objects that would otherwise be impossible to print on, such as pens and keyboards. A silicone plate is used to press the image into the surface and because the plate is flexible, it can be applied to almost any shaped surface.
Specialty Printing A range of techniques, such as specialty printing, give a designer the possibility of adding an extra touch of valueadding excitement to a design. • • • • • • • • •
Perforation Duplexing Foils Thermography Embossing Debossing Die Cutting Laser Cutting Kiss Cutting
Laminates & Varnishes Laminates and varnishes are print finishes applied to the printed job to add a finishing touch. A lamiante is a plastic coating that is heat sealed on to the stock to produce a smooth finish and to provide a protective layer to the cover stock. A vanish is a colourless coating, applied to a printed piece to protect it from wear or smudging.
Bibliography - The Production Manual: A Graphic Design Handbook - Wikipedia - Basics Design: Print and Finish - Basics Design: Colour - Google Images - Lecture Notes
The Print Process A graphic designers guide to the print process. Including information on pantone spot colours, printing methods, gamut and other print production techniques.