Abstract: A negative-working lithographic printing plate precursor have an outermost imageable layer that includes an oxygen scavenger and shelf-life stabilizer that is represented by either Structure (I) or Structure (II) below: HOOC—Ar—N(R1)(R2)??(I) HOOC—R5—N(R6)(R7)??(II) wherein Ar is a phenylene or naphthylene group, R1 and R2 are independently alkyl, alkenyl, alkynyl, phenyl, phenoxy, —R5OH, —CH2—C(?O)—R3, or —CH2—C(?O)O—R4 groups, R3 is hydrogen or an alkyl or phenyl group, R4 is an alkyl or phenyl group, R5 is an alkylene group, R6 and R7 are independently hydrogen or an alkyl, —R5OH, —R5C(?O)—R8, or —R5C(?O)OR9 group, R8 is hydrogen or an alkyl group, and R9 is an alkyl group, provided that the oxygen scavenger has no more than one carboxyl group.

Abstract: Lithographic printing plates can be prepared with enhanced contrast between the image and background by coloring the imaged or exposed regions using a coloring fluid containing a water-insoluble colorant (dye or pigment) and an organic solvent that swells the imaged regions sufficiently for the colorant to be embedded or diffused therein.

Abstract: Seasoned lithographic printing plate developer solutions are treated with a hypochlorite to decompose infrared radiation-sensitive cyanine dyes that are released from lithographic elements during alkaline development. The hypochlorite is useful to decompose both suspended and soluble forms of the cyanine dyes so they can be more safely discharged to the environment in the seasoned developer solution. This treatment avoids expensive filtration equipment and incineration for handling seasoned developer solutions before they are discharged to the environment.

Abstract: A negative-working lithographic printing plate precursor have an outermost imageable layer that includes an oxygen scavenger and shelf-life stabilizer that is represented by either Structure (I) or Structure (II) below: HOOC—Ar—N(R1)(R2) ??(I) HOOC—R5—N(R6)(R7) ??(II) wherein Ar is a phenylene or naphthylene group, R1 and R2 are independently alkyl, alkenyl, alkynyl, phenyl, phenoxy, —R5OH, —CH2—C(?O)—R3, or —CH2—C(?O)O—R4 groups, R3 is hydrogen or an alkyl or phenyl group, R4 is an alkyl or phenyl group, R5 is an alkylene group, R6 and R7 are independently hydrogen or an alkyl, —R5OH, —R5C(?O)—R8, or —R5C(?O)OR9 group, R8 is hydrogen or an alkyl group, and R9 is an alkyl group, provided that the oxygen scavenger has no more than one carboxyl group.

Abstract: Lithographic printing plates can be prepared with enhanced contrast between the image and background by coloring the imaged or exposed regions using a coloring fluid containing a water-insoluble colorant (dye or pigment) and an organic solvent that swells the imaged regions sufficiently for the colorant to be embedded or diffused therein.

Abstract: A positive photosensitive composition for use with a radiation source comprises one or more polymers capable of being dissolved in an alkaline aqueous solution and a compound which, upon being heated, releases gas. The composition is stable in its state before exposure and has an excellent handling property. The sensitivity of a recording layer based on the composition of this invention is increased without compromising the handling characteristics. In addition radiation sensitive-elements based on the composition of the invention have good development latitude.