Reproduction of Color with Halftone Images.

Although many techniques have been developed to yield high-quality color reproductions in the graphic arts, the representation of colors with multiple printing of colored halftone dot patterns is not a clearly understood subject. This is borne out by the common, but oversimplified expression that the nature of the halftone process is essentially additive color-mixing in the light tints and subtractive color-mixing in the dark tints. More accurate information concerning the complicated mechanics of the halftone process, and its dependence upon the many variables involved is obtained from a theoretical analysis of the interaction of light with the halftone dot structure. Correlation of data from printed halftone color reproductions serve to show the validity of such theoretical analyses. Based on this understanding of the halftone printing process, the required characteristics of masking are better evaluated. The relationship between the types of masking suitable for continuous-tone work and for halftone reproductions is discussed.