Method of developing a lithographic printing plate including post heating

A method for pre-press development of a negative working lithographic printing plate having a radiation sensitive, oleophilic resin coating adhered to a hydrophilic substrate, comprising:

• initially exposing the coating to a pattern of radiation energy, thereby producing an imaged plate having image areas where the coating is partially cross-linked by reaction with the radiation energy and nonimage areas where the coating is unaffected by the radiation energy;
• developing the plate by removing only the nonimage areas of the coating from the substrate without chemical reaction, thereby producing a pattern of said partially cross-linked oleophilic coating in the image areas and hydrophilic substrate where the nonimage areas were removed;
• and
• finally exposing the developed plate to a source of energy which further reacts and cross links the image areas.

A method for pre-press development of a negative working lithographic printing plate having an oleophilic resin coating that has a cross-linking reaction to imaging radiation, is solvent soluble but not water soluble, has a nominal coating weight, a coating cohesion, and non-ionic adhesion to a hydrophilic substrate that is less than said coating cohesion, comprising:

• initially exposing the coating to a pattern of radiation energy, producing an imaged plate having image areas where the radiation energy produces an initial cross-linking reaction in the coating and thereby increases the cohesion and adhesion of the coating, and nonimage areas where the coating is unaffected by the radiation energy;
• without heating the imaged plate, developing the imaged plate in a water environment by application of mechanical force to dislodge and remove the nonimage areas as undissolved particles from the substrate, thereby producing a pattern of initially cross-linked oleophilic coating in the image areas that retain the nominal coating weight and hydrophilic substrate where the nonimage areas were removed;
• and
• finally exposing the developed plate to a blanket source of energy to produce additional cross-linking reactions in the image areas.