To provide a method for on-press developing having a dampening water purification means for removing an image recording layer component and an over-coating layer component mixed in a dampening water by on-press developing running, in an on-press developing type lithographic printing method.
The method for on-press developing the lithographic printing plate master having on a support the image recording layer containing (A) an IR absorbent, (B) a polymerization initiator and (C) a polymerizable compound, and capable of being removed by a printing ink or a dampening water or by both of them, has the dampening water purifying means comprising the step of at least making filtration to remove the image recording component mixed in the dampening water with a suction filter.
Hironori Honda
Toshimitsu Ichikawa
Takeshi Takamatsu
Yuriko Hamada