Color Differentiation in Reproduction Processes.

The paper describes a method of calculating how accurately small color differences between two colors in an original will be reproduced. In order to do this, the following data are required: (1) measurements of the color densities of the individual inks, (2) information as to the way in which the multicolor print is related to the individual ink images, (3) the tone rendering of the individual ink images, and (4) the characteristics of any masking method which is a part of the reproduction process. The differentiation of nearly neutral colors has been worked out for a number of typical conditions. It is shown that straight-line masks cause overcorrection of the shadows in a three-color process, owing to both additivity and proportionality failure. The effect of the black printer in destroying color differentiation in the shadows is also shown.