Abstract: The present invention provides a silver halide photographic photosensitive material which has a printability from color negatives and which can be used as a variable contrast printing paper. This silver halide photographic photosensitive material comprises a support and at least one silver halide emulsion layer provided on the support wherein when .gamma. (gamma) values of characteristic curves obtained by exposure through filters having a transmission maximum wavelength at about 430 nm, about 540 nm and about 700 nm are indicated by .gamma..sub.B, .gamma..sub.G and .gamma..sub.R, respectively, the following inequalities 0.3<.gamma..sub.G /.gamma..sub.B <0.7 and 0.3<.gamma..sub.G /.gamma..sub.R <1.0 are satisfied. Furthermore, an exposing method is also provided.

Abstract: The present invention provides a silver halide photographic photosensitive material which has a printability from color negatives and which can be used as a variable contrast printing paper. This silver halide photographic photosensitive material comprises a support and at least one silver halide emulsion layer provided on the support wherein when .gamma. (gamma) values of characteristic curves obtained by exposure through filters having a transmission maximum wavelength at about 430 nm, about 540 nm and about 700 nm are indicated by .gamma..sub.B, .gamma..sub.G and .gamma..sub.R, respectively, the following inequalities 0.3<.gamma..sub.G /.gamma..sub.B <0.7 and 0.3<.gamma..sub.G /.gamma..sub.R <1.0 are satisfied. Furthermore, an exposing method is also provided.

Abstract: The present invention provides a lithographic printing plate material for silver complex diffusion transfer process by scanning type exposure which comprises a film support and, provided thereon, at least a silver halide emulsion layer and a surface physical development nuclei layer, wherein water content in the whole lithographic printing plate material including the support is 1.5% or less. Preferably, the silver halide emulsion comprises about 95 mol % or more of silver chloride, 90% by weight or more of the silver halide grains have a size within .+-.40% of average grain size, the silver halide grains have an average grain size of about 0.3.mu.-about 1.0.mu., and the surface of the grains is replaced with about 0.1 mol %-about 3.0 mol % of an iodide per 1 mol of the silver halide.

Abstract: The invention provides a light-sensitive material for making lithographic printing plate through high-intensity short-time exposure which comprises a support and, provided thereon, at least a silver halide emulsion layer and a physical development nuclei layer wherein an intermediate layer comprising a water-permeable film forming polymer is provided between the emulsion layer and the nuclei layer. Furthermore, a process for making a lithographic printing plate from said light-sensitive material is provided which comprises subjecting the light-sensitive material to imagewise exposure of high intensity short time, silver complex diffusion transfer development and subsequently treatment with an oxidizing agent for silver and an oleophilic organic compound.

Abstract: Printing endurance of a lithographic printing plate made by using silver complex diffusion transfer process is markedly improved and besides staining which occurs during printing can be effectively inhibited by containing in at least one of a layer which contains nuclei for physical development comprising a heavy metal of a sulfide thereof and a layer contiguous to said layer at least one water-soluble synthetic polymer having the following structural units: ##STR1## wherein A:B=100:0-50:50 (molar ratio)C:D=100:0-50:50 (molar ratio)(A+B):(C+D)=95:5-5:95 (molar ratio) and R.sub.1 represents a hydrogen atom or an alkyl group of 1-6 carbon atoms, R.sub.2 represents a hydrogen atom or an alkyl group of 1-20 carbon atoms, R.sub.3 represents an alkyl group of 1-20 carbon atoms and M represents a hydrogen atom or a cation.

Abstract: This invention provides a silver halide photographic light sensitive material and a light sensitive lithographic printing plate material which are enhanced in sensitivity to semiconductor laser beam and improved in storage stability and printing endurance. The former comprises a support and a silver halide emulsion layer containing a sensitizing dye having a spectral sensitivity maximum in a wavelength region longer than 700 nm wherein said emulsion layer contains a water-soluble polymer containing a carboxyl group and having a number-average molecular weight of 20,000 or less and the latter comprises a support and, provided thereon, a silver halide emulsion layer containing a sensitizing dye having a spectral sensitivity maximum in a wavelength region longer than 700 nm and a physical development nuclei layer and said emulsion layer contains the above mentioned water-soluble polymer.

Abstract: Disclosed is a silver halide photographic light sensitive material which has a silver halide emulsion layer optically sensitized with a sensitizing dye having a maximum spectral sensitivity in the region of at least 700 nm, said emulsion layer containing at least one compound represented by the following formula (I) or at least one compound represented by the general formula (I) and at least one compound represented by the general formula (II) in combination: ##STR1## (wherein R.sub.1 and R.sub.2 each represents a hydrogen atom, an alkyl group, an aryl group, an aralkyl group, an alkenyl group, an amino group, an acylamido group or a sulfonamido group and sum of carbon atom numbers of R.sub.1 and R.sub.2 is 3 or more.); ##STR2## (wherein R.sub.3 represents an alkyl group of at least 3 carbon atoms or an aryl group).

Abstract: There is provided a method for making a lithographic printing plate having high sensitivity, resolving power and printing endurance and free from scumming utilizing silver complex diffusion transfer process which comprises subjecting to scanning exposure of high-intensity short-time a light sensitive material comprising a support and, provided thereon, at least a silver halide emulsion layer and a physical development nuclei layer as a surface layer and then developing it with a silver complex diffusion transfer developer, the improvement which comprises subjecting the light sensitive material to imagewise exposure with scanning light of at least 700 nm, said emulsion layer containing silver halide grains mainly composed of silver chloride and a sensitizing dye having a sensitivity maximum in the long wavelength region of at least 700 nm in an amount of 3.times.10.sup.-5 -3.times.10.sup.

Abstract: This invention provides a method for deleting images formed on offset printing plates which comprises treating the surface of undesired portion of the images formed by exposure and development with a deletion fluid which contains a ferric complex salt of an organic acid and 0.3 mol/liter or more of at least one compound selected from the group consisting of a soluble bromide and a soluble iodide. Preferred ferric complex salt is a ferric complex salt of aminopolycarboxylic acid.

Abstract: Lithographic printing plates which have such a high sensitivity as permitting use of semiconductor laser beam of low output, a high resolving power and a high printing endurance and are free from occurrence of scumming are made by a method which comprises imagewise exposing a light sensitive material which comprises a support and at least a silver halide emulsion layer and a surface physical development nuclei layer provided on the support, said emulsion layer comprising silver halide grains which contain at least silver bromide and containing at least one sensitizing dye having a maximum spectral sensitivity in the region of longer than 700 .mu.m and then developing the exposed light sensitive material with a silver complex diffusion transfer developer containing at least a thiocyanate. Further improvement can be obtained by providing an antihalation means to keep the reflectance of a light of longer than 700 .mu.m at 13-40%.

Abstract: Lithographic printing plates which have on a support at least one hardened gelatin-containing layer which contains a photographic gelatin and a low molecular-weight gelatin are improved in printing endurance, e.g., resistances against ink-staining and blinding of image areas.