Provided are a lithographic printing plate precursor including a support, and an image recording layer on the support, in which the image recording layer contains organic particles containing an addition polymerization type resin that has a constitutional unit A having a hydrogen bond-donating site, and a content of the constitutional unit A in the addition polymerization type resin is greater than 20% by mass with respect to a total mass of the addition polymerization type resin; and a method of preparing a lithographic printing plate using the lithographic printing plate precursor.

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.

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.

Provided are a planographic printing plate precursor including a support and an image recording layer on the support, in which the image recording layer contains an organic particle containing a resin that has a constitutional unit A having a cation moiety and a constitutional unit B having an anion moiety; and a method of preparing a planographic printing plate using the planographic printing plate precursor.

Provided are a planographic printing plate precursor including a support and an image recording layer on the support, in which the image recording layer contains an organic particle containing a resin that has a constitutional unit A having a cation moiety and a constitutional unit B having an anion moiety; and a method of preparing a planographic printing plate using the planographic printing plate precursor.

A lithographic printing plate precursor includes an image recording layer on a support, in which the lithographic printing plate precursor has projections which are discontinuously formed on a surface of an outermost layer on a side where the image recording layer is provided, and a melting point of each projection is in a range of 70° C. to 150° C. A method of producing a lithographic printing plate includes a step of image-wise exposing the lithographic printing plate precursor to form an exposed portion and an unexposed portion, and a step of supplying at least one of printing ink or dampening water to remove the unexposed portion.

A lithographic printing plate precursor includes an image recording layer on a support, in which the lithographic printing plate precursor has projections which are discontinuously formed on a surface of an outermost layer on a side where the image recording layer is provided, and a melting point of each projection is in a range of 70° C. to 150° C. A method of producing a lithographic printing plate includes a step of image-wise exposing the lithographic printing plate precursor to form an exposed portion and an unexposed portion, and a step of supplying at least one of printing ink or dampening water to remove the unexposed portion.

A halftone raster image, suitable for rendering a continuous-tone image, which comprises a plurality of regularly tiled spiral dots. Said spiral dots comprise (i) image pixels arranged as a first arc (200) or as a plurality of arcs which together represent a first spiral (100), and (ii) non-image pixels arranged as a second arc (201) or as a plurality of arcs which together represent a second spiral (101), wherein neighbour halftone dots from said plurality of regularly tiled halftone dots represent a double spiral or triple spiral.

A halftone raster image, suitable for rendering a continuous-tone image, which comprises a plurality of regularly tiled spiral dots. Said spiral dots comprise (i) image pixels arranged as a first arc (200) or as a plurality of arcs which together represent a first spiral (100), and (ii) non-image pixels arranged as a second arc (201) or as a plurality of arcs which together represent a second spiral (101), wherein neighbour halftone dots from said plurality of regularly tiled halftone dots represent a double spiral or triple spiral.

A negative-working lithographic printing plate precursor includes a coating including vinylogous vitrimer particles. The vinylogous vitrimer particles include a resin having at least one moiety of formula (I), (II), and/or (III): ##STR00001##