| 摘要 |
PROBLEM TO BE SOLVED: To provide a treating method for a positive photosensitive planographic printing plate, firstly, free from occurrence of residual films at the time of development, secondly, capable of providing an excellent printed picture because of no occurrence of finger-print fouling at the time of printing, and, thirdly, improved in environmental qualification and handling safety. SOLUTION: In this treating method for a positive-type photosensitive planographic printing plate, the positive-type photosensitive planographic printing plate provided with a layer of a positive-type photosensitive composition on an aluminum support body, surface-roughened and anodized, having double- structured roughened surface shape with small pits superimposed on large waves, where the average opening diameter d1 (μm) of the small pits is not less than 0.1μm and not more than 3μm while a ratio h/d1 of the average depth h (μm) of the small pits to the average opening diameter d1 (μm) is 0.2 or less, is developed by a developer substantially not including a silicate. |
