Method of processing on-press developable lithographic printing plate having overcoat

A method of processing a lithographic printing plate, comprising in order:

• (a) providing a lithographic plate comprising (i) a hydrophilic substrate, (ii) an oleophilic photosensitive layer comprising a polymeric binder, a free radical polymerizable monomer, a free radical initiator, and a sensitizing dye, and (iii) an overcoat;
• where said photosensitive layer is soluble or dispersible in ink and/or fountain solution and capable of hardening upon exposure to a laser having a wavelength selected from 200 to 1200 nm, and said overcoat is coated onto said photosensitive layer from an aqueous solution or dispersion comprising a water soluble polymer;
• (b) imagewise exposing said plate with said laser to cause hardening of said photosensitive layer in the exposed areas;
• (c) removing said overcoat from said plate by mechanical peeling, wherein the overcoat is removed by applying a mechanical force to pull off or drive off the overcoat from the plate as a single piece or more than one piece of film;
• and
• (d) contacting said plate with ink and/or fountain solution on a lithographic press to remove the photosensitive layer in the non-hardened areas.

A method of processing a lithographic printing plate, comprising in order:

• (a) providing a lithographic plate comprising (i) a hydrophilic substrate, (ii) an oleophilic photosensitive layer comprising a polymeric binder, a free radical polymerizable monomer, a free radical initiator, and a sensitizing dye, and (iii) an overcoat;
• wherein said photosensitive layer is soluble or dispersible in ink and/or fountain solution and capable of hardening upon exposure to a laser having a wavelength selected from 200 to 1200 nm, and said overcoat is laminated onto said photosensitive layer from a polymeric film which is pre-coated with an adhesive layer;
• (b) imagewise exposing said plate with said laser to cause hardening of said photosensitive layer in the exposed areas;
• (c) peeling off said overcoat from said plate as a single film, wherein the overcoat is removed by applying a mechanical force to pull off or drive off the overcoat from the plate as a single piece or more than one piece of film;
• and
• (d) developing said plate with ink and/or fountain solution on a lithographic press to remove the photosensitive layer in the non-hardened areas.