Дослідження впливу офсетних друкарських форм CtP на репродукційно-графічні показники відбитків

Abstract

In this study, the reproduction and graphic parameters of printing plates made by CtP technology of popular brands were investigated that are represented in the Ukrainian market of printing consumables.As a result of the research, graphic dependencies were built that allow estimation of the reproduction quality of color images in offset printing under given conditions and determine the maximum compliance with the original.As a result of experimental studies of print imprints using thermal offset plates, the following results of color reproduction of the images were obtained: for the blue printing ink, the optical density of the image is as close as possible to the color test in sample No. 2 for all studied raster lines and in sample No. 1 in the case of stochastic screening; for plates No. 2 and No. 3, there was no significant difference in the gradation of the transfer of purple printing ink during regular screening, since practically identical indices of optical density of dies, contrast and saturation of the image were obtained, whereas in stochastic screening the density indices coincide only in light areas; slight deviation of density is observed at regular screening for a yellow printing ink and practically the perfect match for stochastic screening for three sets of printing forms; a positive result was found in the investigated plates in all the raster lines for a black printing ink, however, from the areas of the halftones there are deviations from the color test in stochastic screening.Analysis of the comparison of ton reproduction in the system ‘colorproof—print imprint’ showed slight, visually not noticeable deviations. However, for high-art works, it is recommended to use stochastic screening, which takes into account the set of points needed to display the required intensity of the tone in the raster cell.