= Cyan, Magenta, Yellow and Key (Black). Device dependent colour space in print. Cyan, magenta and yellow are the basic colours of subtractive colour mixing. Black must be added because the colours cyan, magenta and yellow cannot be used to produce pure black.

Convert RGB to CMYK

Image data is usually digitised to RGB (using a scanner or digital camera) and then converted to CMYK.

RGB-CMYK colour circle