Abstract: The method of preparing a lithographic printing plate precursor according to the present invention comprises the steps of: providing an aluminum support; graining and anodizing the aluminum support; without applying a hydrophilic layer on the anodized aluminum support, coating a composition which is photopolymerizable upon absorption of light having a wavelength in the range of from 350 nm to 450 nm and comprising a polymerizable monomer or oligomer, a binder and a photo-initiator on the grained and anodized aluminum support to form a photopolymerizable layer; coating an overcoat on the photopolymerizable layer; characterized in that the ratio of the total solid amount of polymerizable monomer and oligomer to the total solid amount of binder is from 1.0 to 2.0.

Abstract: A positive working heat-sensitive lithographic printing plate precursor is disclosed which comprises a support having a hydrophilic surface and a coating, provided on the hydrophilic surface, wherein the coating comprises a spacer particle comprising aluminum hydroxide or aluminum oxide and having an average particle size larger than 0.3 ?m, for improving the scuff-mark resistance of the coating. Furthermore, the coating comprises an infrared light absorbing agent, an oleophilic resin soluble in an aqueous alkaline developer and a developer resistant means.

Abstract: A positive working heat-sensitive lithographic printing plate precursor is disclosed which comprises a support having a hydrophilic surface and a coating, provided on the hydrophilic surface, wherein the coating comprises a spacer, which is a cross-linked polysiloxane particle, having a particle size larger than 0.6 &mgr;m, for improving the scuff-mark resistance of the coating. Furthermore, the coating comprises an infrared light absorbing agent, an oleophilic resin soluble in an aqueous alkaline developer and a developer resistant means.

Abstract: A positive working heat-sensitive lithographic printing plate precursor is disclosed which comprises a support having a hydrophilic surface and a coating, provided on the hydrophilic surface, wherein the coating comprises a spacer particle comprising aluminum hydroxide or aluminum oxide and having an average particle size larger than 0.3 &mgr;m, for improving the scuff-mark resistance of the coating. Furthermore, the coating comprises an infrared light absorbing agent, an oleophilic resin soluble in an aqueous alkaline developer and a developer resistant means.