| abstract |
Provided is an original plate for an on-press development type lithographic printing plate, the original plate comprising a supporting body and an image recording layer provided on the supporting body, wherein: the image recording layer contains an initiator, an infrared absorbing agent capable of donating electrons to the initiator, and a chromogenic body precursor; the image recording layer is capable of forming an image by means of infrared laser exposure; and, when the image recording layer is exposed by infrared laser exposure with a wavelength of 830 nm and an energy density of 110 mJ/cm2, a luminosity change ∆L in the image recording layer before and after the exposure is no less than 3.0. Also provided is a lithographic printing plate fabricating method or a lithographic printing method using the original plate for an on-press development type lithographic printing plate. |