print colour
This section helps the designer understand the colour systems that can be applied in print. Starting with looking at the application of CMYK and spot colours and then the application of other colour systems to such as tones and tints.
subtractive colour When we mix colours using paint, or through the printing process, we are using the subtractive colour method. Subtractive colour mixing means that one begins with white and ends with black; as one adds colour, the result gets darker and tends to black.Â
Additive colour is referred to as RGB or screen based colours not used in print. Printing presses use this colour system in inks that act as filters and subtract portions of the white light striking the image on paper to produce other colours.
CMYK Stand for Cyan, Magenta, Yellow and Key (Black) and is described also as the four process colours used within print. Printing that uses these four standard colours is often referred to as four colour printing. Issues can arise when working a brand across print and digital, as converting the same CMYK colour to a
different colour mode of RGB (red, green and blue) it is difficult to achieve the exact same, in the majority of cases this is not possible and is colour matched to the next closest possibility.
spot colour Spot colours are made from various base elements, mixed according to specific amounts. Spot colour inks can be bought pre-mixed and ready to use or they can be created by mixing the constituent parts. They are applied directly as one flat colour so they appear brighter more intense colour on the page and can be used to make an element of the design stand out more than the rest of the page.
Pantone P 37-6 C Spot colour
C=0 M=49 Y=65 K=12 CMYK colour
tints A tint is a colour shade that is predominately white in colour. Inks can be printed in tints of the same colour to produce what appears like a spectrum of colours which is a cost effective way to produce a tonal image when printing. Colours can be printed in increments of 10% to produce around 1,330 different tints and almost 15,000 when including black. To see how tints would appear on the finished product a bar can be printed on the trim edge, this is the only way to see how the low times will register. Tints below 10% and those above 90% may not print accurately due to the effect of the dot gain.
Pantone system The Pantone PMS colour system has developed to include a wide range of different colours, including special solid, hexachrome, metallic and pastel colours. This system allocates a unique reference number to each hue and shade which is used to easily communicate the colour wanted between you and the printers. And the guides off a collection of over 3,000 CMYK colour choices. The letter suffix refers to the paper stock on which it is printed. C for coated or gloss paper U for uncoated paper M for matte or dull paper
halftone A halftone is an image composed of different size dots which reproduce the continuous tones within the image. These dots can vary in either size, shape or spacing and act similar to that of an optical illusion. This colour method allows the number of tonal colour inks needed to create one image be reduced to one or a small amount, reducing the printing costs dramatically but still achieving the same finished visual quality. This colour method is sometimes used within a screen printing process in which the screen angle is changed and rotated for each colour to reproduce the image more accurately.
Round dots: most common, suitable for light images, especially for skin tones. They meet at a tonal value of 70%. Elliptical dots: appropriate for images with many objects. Elliptical dots meet at the tonal values 40% (pointed ends) and 60% (long side), so there is a risk of a pattern. Square dots: best for detailed images, not recommended for skin tones. The corners meet at a tonal value of 50%. The transition between the square dots can sometimes be visible to the human eye.
monotone, duotone, tritone, quadtone These are images within the publication that the tones within them are created using either one colour, two, three or four depending on which mode working with. They are often used in conjunction with a Pantone system ink.
Monotone
Duotone
Tritone
Quadtone
overprinting This is where one ink overprints another so that they mix to create different colours. Different blacks can also be achieved with overprinting. To achieve this effectively as a designer you need to keep in mind the order in which the process colours print. If printing in the order cyan, magenta, yellow and black, the yellow obviously cannot overprint cyan. Overprinting can produce creative effects when used with graphic images.
The four process colours overprint on the stock.
Each colour knockout is printed in the deafault colour order.
The colours can also overprint one another in the printing.
All four process colours can overprint to create a stronger black colour.