Based on evaporation of fountain solution from a rotating blanket cylinder to create an image that may be inked and printed, a digitally addressable heater array at or just below the blanket surface evaporates deposited fountain solution and forms a fountain solution latent image on the surface. The heater array has controllable heating elements (e.g., field effect transistors, thin film transistors) that provide a transient heat pattern on the surface to evaporate the fountain solution. Heat is generated by current flow in the heating elements, and power developed by the heating circuit is the product of source-drain voltage and current in the channel. Current may be supplied along data lines by an external voltage controlled by digital electronics to provide the desired heat at heating elements addressed by a specific gate line. The heater array may include a current return line that may be a 2-dimensional mesh.

An object of the present invention is to provide a lithographic printing plate precursor from which a lithographic printing plate with excellent oil-based cleaner printing durability is obtained, a method of producing a lithographic printing plate, a printing method, and a method of producing an aluminum support. The lithographic printing plate precursor of the present invention is a lithographic printing plate precursor including an aluminum support, and an image recording layer disposed on the aluminum support, in which the aluminum support includes an aluminum plate and an anodized aluminum film disposed on the aluminum plate, the image recording layer is disposed on the aluminum support on a side of the anodized film, and an area ratio of projections with a height of 0.80 μm or greater from an average level, which is obtained by measuring a surface of the aluminum support on a side of the image recording layer in an area of 400 μm×400 μm using a non-contact three-dimensional roughness meter, is 20% or less.

A lithographic printing plate precursor is disclosed including a support and a coating comprising a photopolymerisable layer including a polymerisable compound, a photoinitiator, and an infrared absorbing compound including a long chain linear or branched alkyl group.

IR-sensitive lithographic printing plate precursors provide a stable print-out image using a unique IR-sensitive image-recording layer. The IR radiation-sensitive layer includes: (1) a free radical initiator composition with an electron-donating agent and one or more iodonium cations; (2) a free radically polymerizable composition; and (3) a color-changing compound of Structure (I) having an indene ring in the conjugated chain between the aromatic terminal groups. The IR radiation-sensitive composition and layer also contains one or more borate ions such that the molar ratio of one or more borate ions to the one or more iodonium ions is at least 0.5:1. After IR imaging, these precursors exhibit desirable printout images both fresh and after dark storage. The precursors can be developed on-press.

A halftone raster image, suitable for rendering a continuous-tone image, which comprises a plurality of dots, arranged according a screen ruling and screen angle. Said dots comprise (i) image pixels arranged as a first arc or as a plurality of arcs which together represent a first spiral, and (ii) non-image pixels arranged as a second arc or as a plurality of arcs which together represent a second spiral. Small displacements of the feed point of said dots away from the theoretical centre of a halftone dot, defined by said screen ruling and screen angle, enable a higher image quality and less patterns in said halftone raster image.

A halftone raster image, suitable for rendering a continuous-tone image, which comprises a plurality of dots, arranged according a screen ruling and screen angle. Said dots comprise (i) image pixels arranged as a first arc or as a plurality of arcs which together represent a first spiral, and (ii) non-image pixels arranged as a second arc or as a plurality of arcs which together represent a second spiral. Small displacements of the feed point of said dots away from the theoretical centre of a halftone dot, defined by said screen ruling and screen angle, enable a higher image quality and less patterns in said halftone raster image.

A photosensitive resin structure for a printing plate, containing: a support (A); a photosensitive resin composition layer (B) comprising a thermoplastic elastomer (B-1) comprising a monovinyl-substituted aromatic hydrocarbon and a conjugated diene, an ethylenically unsaturated compound (B-2), and a photopolymerization initiator (B-3); and a non-infrared ray-shielding layer (C) ablatable with an infrared ray, wherein the non-infrared ray-shielding layer (C) comprises a polymer (C-2) having a carboxylate group and an ester bond group in a molecule thereof and an infrared ray absorber (C-3), and a proportion of an ester bond group such that carbon bonded to the ester bond group and carbon bonded to the carboxylate group are adjacent to each other in all the ester bond groups contained in the polymer (C-2) is 15% or more.

A photosensitive resin structure for a printing plate, containing: a support (A); a photosensitive resin composition layer (B) comprising a thermoplastic elastomer (B-1) comprising a monovinyl-substituted aromatic hydrocarbon and a conjugated diene, an ethylenically unsaturated compound (B-2), and a photopolymerization initiator (B-3); and a non-infrared ray-shielding layer (C) ablatable with an infrared ray, wherein the non-infrared ray-shielding layer (C) comprises a polymer (C-2) having a carboxylate group and an ester bond group in a molecule thereof and an infrared ray absorber (C-3), and a proportion of an ester bond group such that carbon bonded to the ester bond group and carbon bonded to the carboxylate group are adjacent to each other in all the ester bond groups contained in the polymer (C-2) is 15% or more.

Fountain solution latent images are provided on an inking blanket without using laser-induced evaporation systems. Approaches include a rotatable charge retentive surface configured to receive an unfused toned electrostatic pattern of toner particles adhered thereto via electrophotography. The toner includes small diameter polymeric or inorganic particles that may have no color pigment to appear transparent or translucent. Fountain solution is disposed on at least one of the toner, the charge retentive surface and a transfer substrate. The transfer substrate is adjacent the charge retentive surface and forms a nip therebetween, with the transfer substrate sandwiching the unfused toned electrostatic pattern of toner particles and fountain solution against the charge retentive surface at the nip. Fountain solution sandwiched between the surfaces splits as the surfaces separate downstream the nip, leaving a fountain solution latent image remaining on the transfer member surface based on the electrostatic charged pattern on the charge retentive surface.

A lithographic printing plate precursor is disclosed including a support and a coating comprising (i) a photopolymerisable layer including a polymerisable compound and a photoinitiator, and a toplayer provided above the photopolymerisable layer; characterized in that the toplayer has a thickness comprised between 0.1 g/m.sup.2 and 1.75 g/m.sup.2 and includes an infrared absorbing compound which includes a thermocleavable group which transforms into a group which is a stronger electrondonor upon exposure to heat and/or IR radiation, and is capable of forming a printout image upon exposure to heat and/or IR radiation.