four-color process

halftone printing process utilizing four ink colors (black, magenta, cyan, yellow) to produce a printed image that matches the coloring of the original image. Four-color process printing is more expensive than two-color printing but has a greater impact on the viewer. It is accomplished by creating a color separation for each of the three primary colors perceived by the human eye: blue, red, and green. The image is photographed through blue, red, and green color filters, producing a negative for each color that effectively blocks out that color. The red filter produces a cyan positive; the green filter, a magenta positive; the blue filter, a yellow positive. The three positives are combined to produce a preliminary print that requires the addition of black and variations in the primary color proportions to achieve the desired effect. Four-color process is used in gravure, letterpress, offset, and screen printing. See also color correction; duplicating film; progressive proofs; two-color process.