Abstract: The present invention provides a planographic printing element suitable to receive and bond with a subsequently applied hydrophilic layer comprises a substrate layer, such as polyester film or paper, having coated thereon an adhesion layer, said adhesion layer comprising a polymer having a glass transition temperature of less than 15C and containing functional groups such as hydroxyl, epoxy or glycidyl groups capable of reacting with the hydrophilic layer. The polymer may be a terpolymer of a hydroxyalkyl methacrylate, an alkyl acrylate and an aminoalkyl methacrylate. The polymer may be mixed with gelatin and the mixture applied to the substrate as a coating. The hydrophilic layer, which may comprise metal oxide particles, such as aluminium oxide and/or titanium dioxide particles in a sodium silicate binder, is subsequently applied as a coating to the adhesion layer.

Abstract: A planographic printing element suitable to receive and bond with a subsequently applied hydrophilic layer comprises a substrate layer such as polyester film or paper having coated thereon an adhesion layer, said adhesion layer comprising a polymer having a glass transition temperature of less than 15° C. and containing functional groups such as hydroxyl, epoxy or glycidyl capable of reacting with the hydrophilic layer. The polymer may be a terpolymer of a hydroxyalkylacrylate, an alkyl acrylate and an aminoalkylmethacrylate. The polymer may be mixed with gelatin and the mixture applied to the substrate as a coating.

Abstract: A method for correcting mistakes and other imperfections in printing members is disclosed. Ink accepting areas of the printing member are rendered non-ink accepting by treatment with a deletion fluid. Deletion fluids include, for example, acids, alkalis, and oxidizing formulations. A preferred deletion fluid is concentrated sulfuric acid.

Abstract: A method for preparing a substrate for a planographic printing member is disclosed. A liquid that contains water; a soluble alkali metal silicate, preferably sodium silicate; and a dispersed particulate material is coated on a support, to produce a hydrophilic layer on the support. A layer of image material may be coated over the hydrophilic layer to produce a planographic printing member. In one embodiment the liquid contains a mixture of two particulate materials, preferably alumina and titanium dioxide. The substrate has a surface roughness of about 0.1 &mgr;m to 2 &mgr;m. The substrate is suitable for preparing a planographic printing member processable to a resolution of 10 &mgr;m or less and in which the dots having a roundness of less than 2 are formed.

Abstract: A planographic printing member comprising a substrate, an oleophilic layer, an infra-red sensitive/ablatable layer, and a hydrophilic layer. The hydrophilic layer is derived from a silicate solution, optionally containing particulate materials such as alumina and/or titania. The printing member may be exposed to radiation from a laser which ablates the infra-red sensitive/ablatable layer to reveal areas of the oleophilic layer. An exposed printing member may be used in wet lithographic printing.