Abstract: A printing plate is prepared by the process comprising: (a) providing a substrate; and (b) applying by ink jetting to the substrate a fluid composition comprising a cationic polymer and an anionic polymer, in non-aqueous solvent. The ionic polymers interact and adhere to the substrate, so that after drying a durable printing plate is formed, without chemical development. The printing plate of this invention is capable of extended press run length and advantageously avoids the need of chemical development.

Abstract: A lithographic printing plate, in which (1) the non-image area of a hydrophilic swellable layer is 1 to 50 g/m.sup.2 in water absorbability, and the water absorbability of the image area is less than that of the non-image area, (2) the non-image area of a hydrophilic swellable layer is 0.01 to 10 kg/mm.sup.2 in initial modulus, and the initial modulus of the image area is larger than that of the non-image area, (3) the non-image area of a hydrophilic swellable layer is 10 to 2000% in water swelling ratio, and the water swelling ratio of the image area is less than that of the non-image area, or (4) the hydrophilic swelling layer has a phase separated structure consisting of at least two phases; a phase mainly composed of a hydrophilic polymer and a phase mainly composed of a hydrophobic polymer, can be produced from a new photosensitive lithographic original plate simple in development treatment, highly repellent against ink even without being etched, and allowing the use of pure water as dampening water.

Abstract: A moistening agent and method for its use in offset printing plates is described. The agent contains a low molecular weight cationic protein as a water soluble, major component.

Abstract: A moistening agent and method for its use in offset printing plates is described. The agent contains native soluble non-crosslinked collagen and/or non-crosslinked elastin as a water-soluble organic polymer.

Abstract: An electrostatic master for lithographic printing characterized by a base, a barrier coat thereon, and a photo-conductive layer. The barrier coat includes a hydrophobic thermoplastic film-forming resin having labile hydrogen-containing functional groups and a conductive agent. The conductive agent is a quaternary ammonium salt. The salts have only a minimal effect on water resistance and result in excellent reduction in the dielectric characteristics of the barrier coat.

Abstract: Laminates for the production of relief plates for flexographic printing, by imagewise exposure and washing out with a developer solution have, on a base optionally provided with an elastomeric layer, a photo-crosslinkable layer containing a photoinitiator and consisting of a polyurethane elastomer which has been prepared in a special manner from an aliphatic saturated polyesterglycol, an aliphatic diisocyanate, but-1-ene-3,4-diol and, if desired, another diol and which has a Shore A hardness of 30 to 90.degree. in the photo-crosslinked state, the elastomer being optionally mixed with a photo-crosslinked monomer.