Provided are a lithographic printing plate precursor including: a hydrophilized aluminum support, and a water-soluble or water-dispersible negative type image recording layer provided on the aluminum support, in which an arithmetic average height Sa of a surface of an outermost layer on a side opposite to a side where the image recording layer is provided is in a range of 0.3 m to 20 m; a method of producing the lithographic printing plate precursor; a lithographic printing plate precursor laminate formed of the lithographic printing plate precursor; and a lithographic printing method.

Provided are a lithographic printing plate precursor for furnishing a lithographic printing plate in which adhesion to interleaving paper is prevented, contamination inside a device is prevented, and edge stain does not occur; a method of producing the same; and a printing method using the same. The lithographic printing plate precursor includes: a support; and an image recording layer on the support, in which a region of a surface of the lithographic printing plate precursor at a side of the image recording layer, which is from an end portion of the lithographic printing plate precursor to a portion inside the end portion by 5 mm, contains at least one polymer selected from polyamide, polyurethane, polyurea, polyester and polycarbonate, and has a content of the polymer per unit area which is greater than a content of the polymer per unit area in a region other than the above-described region by an amount of 10 mg/m.sup.2 or greater.

Provided are a lithographic printing plate precursor for furnishing a lithographic printing plate in which adhesion to interleaving paper is prevented, contamination inside a device is prevented, and edge stain does not occur; a method of producing the same; and a printing method using the same. The lithographic printing plate precursor includes: a support; and an image recording layer on the support, in which a region of a surface of the lithographic printing plate precursor at a side of the image recording layer, which is from an end portion of the lithographic printing plate precursor to a portion inside the end portion by 5 mm, contains at least one polymer selected from polyamide, polyurethane, polyurea, polyester and polycarbonate, and has a content of the polymer per unit area which is greater than a content of the polymer per unit area in a region other than the above-described region by an amount of 10 mg/m.sup.2 or greater.

A curable composition includes an infrared absorber having at least one element in Group XIII of the periodic table on a mother nucleus structure and having a chain-like polymethine structure, in which two or more hetero atoms are bonded to carbon atoms at non-meso positions. Also, a lithographic printing plate precursor in which the curable composition is used, and a method for producing a lithographic printing plate in which the lithographic printing plate precursor is used are provided.

A curable composition includes an infrared absorber having at least one element in Group XIII of the periodic table on a mother nucleus structure and having a chain-like polymethine structure, in which two or more hetero atoms are bonded to carbon atoms at non-meso positions. Also, a lithographic printing plate precursor in which the curable composition is used, and a method for producing a lithographic printing plate in which the lithographic printing plate precursor is used are provided.

Provided is a precursor for lithographic printing having excellent printing durability and ink repellency as well as high reproducibility of the high definition images. The precursor for lithographic printing includes, at least a heat sensitive layer and an ink repellent layer wherein the ink repellent layer has an elastic modulus of the plate surface under the surface load of 14000 N/m2 of at least 25 MPa and up to 35 MPa.

Provided is a precursor for lithographic printing having excellent printing durability and ink repellency as well as high reproducibility of the high definition images. The precursor for lithographic printing includes, at least a heat sensitive layer and an ink repellent layer wherein the ink repellent layer has an elastic modulus of the plate surface under the surface load of 14000 N/m2 of at least 25 MPa and up to 35 MPa.

Negative-working, radiation-sensitive printing plates include or consist of a hydrophilic first layer or substrate and, thereover, an oleophilic imaging layer that includes an iodonium borate free-radical initiators in accordance herewith have the structure

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where X and Y are alkoxy, p and q range independently from 0 to 5, and p+q5; or p and q may range independently from 0 to 4, with p+q4.

Negative-working, radiation-sensitive printing plates include or consist of a hydrophilic first layer or substrate and, thereover, an oleophilic imaging layer that includes an iodonium borate free-radical initiators in accordance herewith have the structure

##STR00001##

where X and Y are alkoxy, p and q range independently from 0 to 5, and p+q5; or p and q may range independently from 0 to 4, with p+q4.

Provided are a planographic printing plate precursor, a laminate thereof, and a method of producing a planographic printing plate precursor capable of satisfying all purposes for eliminating interleaving paper used for preventing scraping and peeling, preventing adhesion, imparting a plate-separating property for preventing multiple-plate feeding, and preventing scratches. The planographic printing plate precursor which includes a polymer layer on a surface of a belt-like support 12 includes a back coat layer 70 having an arithmetic average surface roughness Ra of 0.5 m or greater due to a surface roughness structure in which thin film portions 60 and thick film portions 62 are continuously formed on a rear surface of the belt-like support 12.