A New Densitometric Quality Control System for Offset Printing.

If we want to control the quality of offset printing, we need to control the following factors: the amount of ink, density of the solid, the tone reproduction density of the tints, the slur or doubling the color balance, trapping, and the register. A color control strip is described that is small 1/4 inch wide and yet permits the above factors to be conveniently controlled. Several special features make this system a significant improvement over systems presently available. The specially designed color control bar, in conjunction with special graph paper, permits the statistical analysis of tone reproduction and the evaluation of dot gain in addition to the more conventional application of controlling ink film thickness. These features permit aim values and ranges to be set up for proofing and production work. Other special features of the control strip permit easy handling by strippers, platemakers and press operators. One of the basic experiments that had to be performed in order to design this color control system is explained.