Cyan (blue), magenta (process red), yellow (process yellow), black (process black). Catalogue printing, pads, envelopes - no problem. Contact GSINC
Yellow, magenta, and cyan, so selected because when combined they produce black and when used in various strengths and combinations, they reproduce thousands of different colours with a minimum of photography, platemaking, and presswork.
The colours needed for four colour process printing - cyan, magenta, yellow and black.