What is CMYK four color process printing?
CMYK four color process printing is a system where a color image is photographically separated into four separate color values (called a “color separation”) by the use of filters and screens. This used to be done with photographic film on a graphic arts camera to create CMYK film transparencies; this process is now done digitally. The result four separate pieces of film in four separate colors (Cyan, Magenta, Yellow, and Black) which, when transferred to printing plates and printed sequentially with inks of those colors, reproduces the original color image. Through the control of the density of the ink being applied, a very precise and wide variety of color values can be achieved, allowing those four inks to print millions of different colors. The four color printing process is used universally in the graphic arts and commercial printing industry for the reproduction of color images and text.
Cyan, Magenta, and Yellow are the three main pigments used for color reproduction. When combined in printing, the result should be a reasonable reproduction of the original, but it is not. Due to limitations in the ink pigments, the darker colors are dirty and muddied. To resolve this, the Key, or Black Layer separation is also created, which improves the shadow and contrast of the images and the legibility of black text.
