摘要:
A method of screening a continuous tone image into a halftone representation for a flexographic printing operation can compensate for characteristic printing problems in highlight areas by selectively placing non-printing dots or pixels proximate highlight dots. The non-printing dots or pixels raise the printing relief floor in the highlight areas providing additional support for marginally printable image features.
摘要:
A method of screening a continuous tone image into a halftone representation for a flexographic printing operation can compensate for characteristic printing problems in highlight areas by selectively placing non-printing dots or pixels proximate highlight dots. The non-printing dots or pixels raise the printing relief floor in the highlight areas providing additional support for marginally printable image features.
摘要:
What is proposed is a high-frequency raster with an irregular structure of raster elements. This raster is a plane-parallel glass plate with transparent roughnesses on its surface characterized by a value Ra equal to 0.20-0.26 mu.The high-frequency raster with an irregular structure of raster elements is preferably prepared by a method in which a glass plate is ground at two sides to obtain a uniform structure of the surface. The ground plate is subjected to etching to obtain transparent microroughnesses with a value Ra equal to 0.20-0.26 mu.The raster proposed by the present invention is characterized by a high resolving power in the order of 25 mm.sup.-.sup.1, transmits a normal interval of optical densities of 1.0 to 1.2 and is capable of reproducing an image with a finely grained discrete structure.