Abbreviation referring to the four inks used in color printing:
Cyan,
Magenta,
Yellow, and
Key black. According to some, black ink is called
K (key) because the four colours are aligned with the key of the black
key plate, the plate that contains more details to be printed. According to others, the K comes from the last letter in
black and was chosen because B already means
blue: but
blue is not a primary colour,
cyan is