A color developing composition containing a compound represented by the Formula (1) as defined herein, a lithographic printing plate precursor including a support and an image-recording layer containing the color developing composition, a method for producing a lithographic printing plate including: exposing the lithographic printing plate precursor in an image pattern; and removing a non-exposed portion in the image-recording layer using at least one of printing ink or dampening water on a printer, and a color developing compound represented by the Formula (1) as defined herein.

Dry, ablation-type, nitrocellulose-containing lithographic printing members include dual adjacent imaging layers, both including an absorber and at least one containing a binder (which may include or consist essentially of a melamine resin). The absorber of the nitrocellulose-containing layer is a pigment and this layer contains no absorbing dye, while the absorber of the other imaging layer includes or consists essentially of a dye.

A laser-engravable pad printing plate comprising at least (a) a metal support, (b) an adhesion layer, (c) a laser-engravable recording layer having a layer thickness of 20 ?m to 200 ?m, (d) a cover film,
characterized in that the laser-engravable recording layer (c) comprises (c1) 40 to 95 wt % of a polyvinyl alcohol, (c2) 5 to 50 wt % of an IR absorber, (c3) 0 to 30 wt % of an inorganic filler, (c4) 0 to 20 wt % of a crosslinker, and (c5) 0 to 10 wt % of further additives.

A lithographic printing plate precursor has a substrate comprising a hydrophilic surface and two opposing edges; a radiation-sensitive imagable layer, and optionally, a protective layer disposed over that layer. The precursor has a shear droop at each opposing edge, each shear droop having a shear droop depth Y of 20-200 m and a shear droop width X of 500-2000 m. The precursor also has a hydrophilic coating band extending from each of the two opposing edges inwardly along the hydrophilic surface independently to provide a hydrophilic coating band width A of at least 1.5 times the shear droop width X. This hydrophilic coating band comprises amphoteric surfactant(s) in an amount greater than all other surfactants. Such individual precursors are obtained by cutting a continuous radiation-sensitive web into strips and such cutting creates the shear droop that can result in edge staining if the hydrophilic coating band is not present.

Provided is a printing plate precursor including: a support; a layer which contains a polymer on one side of the support; and a layer which contains a metal oxide obtained by hydrolyzing and polycondensing an organic metal compound or an inorganic metal compound and fine particles on the other side of the support, in which an average particle diameter of the fine particles is 0.3 m or greater and is greater than the thickness of the layer containing a metal oxide and fine particles, and in a case where the printing plate precursors are laminated, dislocation in stacking precursors, adhesion between precursors, and scratches can be all prevented even without using interleaving paper.

An on-press development type lithographic printing plate precursor, including an image-recording layer on a support, in which the image-recording layer contains an infrared absorber A, a borate compound B, an iodonium compound C, and a color forming substance precursor D, and a surface free energy of an outermost layer on an image-recording layer side is 115 mJ/m.sup.2 or less, and a method of preparing a lithographic printing plate, a lithographic printing method, and a laminate using the on-press development type lithographic printing plate precursor.

An on-machine development type planographic printing plate precursor has a support and an image-recording layer on the support. The image-recording layer contains an initiator, an infrared absorber capable of donating electrons to the initiator, and a color-developing substance precursor. The image-recording layer can form an image by exposure to infrared laser, and in a case where the image-recording layer is exposed to an infrared laser with a wavelength of 830 nm at an energy density of 110 mJ/cm.sup.2, a brightness change L of the image-recording layer before and after the exposure is 3.0 or more. A method for preparing a planographic printing plate and a planographic printing method employ the on-machine development type planographic printing plate precursor.

The invention is directed to a lithographic printing plate precursor including, in the following order: a support; an image-recording layer containing a radical polymerizable compound and a radical polymerization initiator; and a protective layer containing a star polymer, and the star polymer is preferably a polymer in which from 3 to 10 polymer chains are branched from a central skeleton.

Provided are a planographic printing plate precursor for furnishing a planographic printing plate in which edge stain does not occur, adhesion to interleaving paper is prevented, and the water width with respect to edge stain at the time of printing is wide; a method of producing the same, and a printing method using the same. The planographic printing plate precursor including: a support; an image recording layer formed on the support; and a water-soluble compound having a molecular weight in a range of 60 to 300 and a solubility of 10 g/L or greater in water at 20 C., in which a content of the compound per unit area in a region on the image recording layer side from an end portion of the planographic printing plate precursor to a portion inside the end portion by 5 mm is greater than a content of the compound per unit area in a second region other than the first region by an amount of 50 mg/m.sup.2 or greater.

There are free radical scavengers of formula (P.sub.m-L).sub.n-T.sub.q. Also provided are negative-working lithographic printing plate precursors comprising a hydrophilic substrate and a NIR photopolymerizable or UV-violet photopolymerizable imageable layer coated on the hydrophilic layer, the imageable layer also being photopolymerizable by visible light, the imageable layer having an outer surface and a thickness, the outer surface of the imageable layer being uniformly, and partially or completely crosslinked down to a depth corresponding to at most about 70% of the thickness of the imageable layer.