| 摘要 |
PURPOSE:To obtain a halftone positive image useful for formation of a block copy by using specific photographic paper and contact screen. CONSTITUTION:The contact screen 2 is superposed on the positive type photographic paper 1 and a continuous tone image 3 which is an original is exposed thereto by an optical system 3 via the contact screen. The positive-positive type photographic paper to be used consists generally of the negative image paper exposed from a transparent positive and a positive film for diffusin transfer of the silver halide in the unexposed part of the negative image paper and the positive-positive type photosensitive material which yields the positive by exposing from the transparent positive and making reversal development is also usable. A magenta contact screen for positive gravure of 60 lines/cm is adequate as the contact screen to be used. |
