Balanced Halftone Separations for Process Color.

In making halftones for black-and-white reproductions, full attention is focused on the problem of the proper tone scale, since color correction and color balance need not be considered. In making halftones for a process color reproduction, the separations must not only be screened in a manner to produce the proper tone scale, but the balance between them must be appropriate for the reproduction of neutral values. Some of the techniques and tools which photographic color printers have successfully applied have been adapted to process color work. For example, the basic concept of equivalent neutral density is a most useful tool in evaluating the color-balance characteristics of a set of halftone separations. The over-all dependence of color balance upon the ink, paper, and printing characteristics is pointed out. A method for determining the END (equivalent neutral density) relationship for a given process has been developed. A practical technique for evaluating a set of halftone separations has also been devised which allows a better understanding of the screening requirements in process color work. This understanding undoubtedly assures a greater degree of success in applying the many excellent masking methods available today.