Color printing typically uses ink of four colors: cyan, magenta, yellow, and black. When subtractive CMY inks are combined at full strength, pairwise combinations are red, green, and blue. Combining all three gives an imperfect black color.

The four process color inks are: Cyan (C), Magenta (M), Yellow (Y) and Black (K - "Key"). CMYK printing involves the use of halftones and screens to distribute the images, illustrations and text into a pattern of dots onto the printing plates which are then transferred to the paper.