CMYK stands for Cyan, Magenta, Yellow, and Key (Black), the standard four-color process used for most commercial printing. Colors are created by layering tiny dots of these inks in varying amounts, allowing full-color images and graphics to be reproduced on paperboard, labels, and many packaging materials.
CMYK is important for packaging and print production because it helps ensure designs are prepared for how inks behave on press and on different substrates. Since CMYK has a different color range than RGB, on-screen colors can shift when printed, so proofs and color management are used to confirm that brand colors and imagery reproduce accurately.