The usage of the silver halide technology in the graphic reproduction is not a novelty. The filmmaking phase is based on the usage of the silver halide as the photographically active ingredient, for instance, AgBr (silver bromide). The new, digital plate making technology (Computer to Plate, CTP) eliminates the filmmaking phase and therefore enables the plate making directly by the computer. The photosensitivity of the silver halide has been used in the Computer to Plate technology as well. The photosensitive copying layer is no long based on diazo type components, which was the case in the conventional plate making systems, today; it is made of silver halide. Not only has the CTP technology eliminated the filmmaking phase, but it has also resulted with the reduction of the quantity of the materials used and required time for the production. In this paper the basis of the graphic reproduction by using the silver halide digital printing plates was described. The changes of the AgX copying layer and the surface of the aluminium base in the printing process have been observed. The surface characteristics were determined by measuring the relevant surface roughness parameters. This also provided insight into the influence of these changes on the quality of the prints. Such measurings are of great value in the graphic reproduction. They enable us to determine the consistency of the printing plates during the printing process, to predict the endurance as well as to define the print run which will result with optimal quality prints.
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