Color printing method

Claim 1

An improved method of preparing half-tone combination primary color and black printing plates and using said plates in a halftone primary color printing process including black line work where the black color is approximated by balancing the primary color components of the print and where the printing process involves using three primary color printing passes only, in a manner known generally per se, comprising, as the improvement, the steps of: a. preparing separated, differentially angled screen images having normal dot densities of the primary color and black components of the combination plates in a manner known generally per se; b. reducing the dot sizes of the normal dot density screen images corresponding to the respective red, blue and yellow components of the combination plates prior to the combining of each image with its respective black component, while leaving the dot sizes of the normal dot density black component of the prepared screen images unreduced; c. preparing combination primary color and black half-tone printing plates in a manner generally known per se using the prepared screened primary color images having reduced dot sizes as the primary color component image of each combination plate; d. printing the final color image using said plates and primary color inks; and e. maintaining the density and volume of said inks during said printing process within a range suitable to maintain optimum color density in the final half-tone image despite the reduction of dot sizes of the primary color components of each printing plate, whereby dense black line work is obtained and the appearance of the half-tone color work is enhanced.