| 摘要 |
The present invention provides a photopolymer printing plate for use in flexographic printing wherein the photopolymer relief structure is composed of printing characters of uniform printing height, the planar printing surfaces of which characters contain a plurality of well-like dimples or depressions present at a density within the range of from about 25 to about 500 depressions per linear inch of planar printing surface. The invention also provides a process for preparing such photopolymer plates by exposing the photopolymer layer to actinic radiation through a photographic mask containing optically transparent areas and optically opaque image areas, the transparent areas of said mask characterized by the presence of a plurality of opaque discrete dots or other geometric shapes present at a density of from about 25 to about 500 dots per linear inch. These dots serve to block a portion of the light passing through the transparent areas of the mask thereby forming discrete regions in the underlying photopolymer layer which are not exposed or are only partially exposed. Upon development of the plate, the regions of the photopolymer layer underlying the dot pattern are removed resulting in the formation of a plurality of depressions in the relief planar surface of the exposed portions of the photopolymer layer. Upon the application of printing ink to the relief printing surface of the plates of this invention, the depressions on the relief surface act as ink reservoirs resulting in the application of a more even distribution of ink to surfaces to be printed, particularly where large solid areas are printed.
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