| 摘要 |
PURPOSE:To form an offset plate capable of obtaining a duplicated print having high density on the dark part, and besides, smooth continuous gradation, by using a synthesized positive formed from 2 kinds of specified screen images. CONSTITUTION:(i) A photosensitive material 4a is exposed to light passed through or reflected with an original and coming through a minute line screen 3a having >= about 200 lines, and developed to form a negative screen image (primary image). (ii) On the other hand, a photosensitive material 4b is alike imagewise exposed through the ordinary screen 3b having <=200 lines, and developed to form a secondary negative screen image 5b. A photosensitive material 6 is doubly exposed successively through the obtained 2 negative images 5a and 5b, and developed to form a synthesized screen positive image 7, and it is printed to a plate material 8 to obtain an offset plate. |
