Process color printing of maps/charts from line/open window negative

Although the four color process printing technique to print from line/open window negatives for aeronautical charts was recognized in 1958, only recently was the process accepted as normal procedure. Improvements in our quality printing techniques have resolved some of the objections of the four color process printing technique while economics of printing five to twelve colors in four remains the overall persuader. Alternative methods of one plate, one press run for each color, and combining two or more conventional chart feature colors to create a third color/feature can be intermixed with four color process printing to avoid some of the quality loss. Four color process printing causes losses in detail resolution and color/texture match.