- Subtractive Colour - Represents inks of pigments that reflect the light of a certain colour, mixed together to make up millions of different colours
- Uses tiny dots of each colour overlapping to create the overall Image
- Colour model for Print
- Additive - Uses the projected red, green and blue light as primary colours to produce the full spectrum of colours. Black is produced by the absence of primary colours.
- Colour model for screen
Colour Management
- The range of spectral colours visible to the human eye can also be described as gamut represented by the image to the left.
- In the print industry the most common gamuts are RGB, CMYK & Hexachrome (CMYKOG - orange and green).
RGB - Can produce around 70% of the colours in the spectral gamut that can be perceived by the human eye.
sRGB - Standard RGB is a standard, device independent, calibrated colour space defined by HP and Microsoft in the 1990's to provide a consistent way to display colour internet images on computer screens
ColourMatch RGB - Has a wider colour space than sRGB and was developed closely to simulate CMYK press work.
Pantone and spot colours
Designers use spot colours to ensure that a particular colour in a design will print. This may be necessary if the colour isn't within the CMYK spectrum. This is often applied within branding to give companies consistent visual identities.
Pantone solid - A range of solid metallic, pastel and process colours that can be used on different paper stocks and substrates.
Pantone Pastels - A range of flat, solid, but very pale colours. Different to tints because they print as a solid colour without visible dots. Available in coated and uncoated swatches.
Pantone Hexachrome - A range of 6 process colours used for hexachrome printing. It adds green and orange to the CMYK process colours allowing it reproduce 90% of the Pantone PMS colours
Pantone Metallics - A range of over 300 special colours that give a metallic effect including silver, gold and copper colours. Available in varnished and unvarnished colour swatches.
- 4 Colour process Guide - Coated / Uncoated
- Colour Bridge - Coated
- Formula Guide - Solid Matt / Solid Coated / Solid Uncoated
U - Uncoated
C - Coated
EC - Euro Coated
M - Matte
- In the other books it also shows the closest CMYK values to that colour.
Spot Colours
Spot colours are made from various base elements, mixed according to a specific recipe. They can be bought pre-mixedand ready to use of they can be created by mixing constituent parts.
Colour Correction
Many image manipulation programs feature colour adjustment features to fix common problems such as red eye and colour balance problems but they can also be used to make sure there isn't to much ink on the page and other such print related issues.
Some of the main colour corrections on Adobe Photoshop are -
Levels, Colour balance, Desaturation, Adjust Contract, Adjust Colour
Many of these have Auto features - Auto Levels, Auto Colour and Auto Contrast but these might not always give you the best results.
Also because digital cameras work in RGB format the conversion to CMYK for print can have a significant effect on the intensity of colours. This however can be checked using 'Gamut Warning' on Photoshop, really useful for making adjustments. This can often be solved by changing the 'hue' and 'saturation' for a print friendly image.
It is also possible to be selective about replacing colour, using the range of selection tools in Photoshop to define the area that needs altering.
Another feature that can be used as a for print is 'Proof Colours', the image becomes slightly duller and is now in a RGB/CMYK format. This provides a preview of how the image will look after conversion for Print. This method gives you less control over the adjustment of your image as 'replace colour' but may be appropriate depending on the job.
- Brightness / Hue / Saturation
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