To provide a plate making method which can form a clear image with high sensitivity without exerting a defect to an image area in spite of preservation for a long period of time, can exhibit specified performance in spite of dissolution of photosensitive layer components into a development processing solution and can suppress the occurrence of development dregs due to the photosensitive layer components.
The method comprises subjecting an original plate for the planographic printing plate which has the photosensitive layer containing a water-insoluble and alkaline water-soluble polymeric compound and an IR absorbent on a support and contains an ester compound having an amount of the residual solvent in the photosensitive layer of ≤5wt% in the total solid content and having a boiling point of ≥160°C under atmospheric pressure to exposure with IR rays, then to development processing with an alkaline development processing solution containing a polyhydric alcohol type nonionic surfactant.
KAWACHI IKUO
Hironori Honda
Toshimitsu Ichikawa
Takeshi Takamatsu
Yuriko Hamada