CMYK refers to the four ink plates used in some color printing: cyan, magenta, yellow, and key (black). The CMYK model works by partially or entirely masking colors on a lighter, usually white, background. The ink reduces the light that would otherwise be reflected.
About color separations When inked with the appropriate color and printed in register with one another, these colors combine to reproduce the original artwork. The process of dividing the image into two or more colors is called color separating, and the film from which the plates are created are called the separations.
There are a handful of separation processes that screen printers use. Understanding the different types of separations, and the challenges they present, can help you execute successful separations on a routine basis. Common screen-printing color separations include: