Abstract: Negative-Working Lithographic Printing Plate Precursors can be provided with desired contrast coloration after imaging using a coloring fluid that includes a water-insoluble colorant that is soluble in a water-insoluble fatty alcohol. The coloring fluid provides an optical density change in the exposed regions of at least OD2 that is greater than the original optical density of those regions, OD1. The coloring fluid can be applied immediately after imaging and before processing, or it can be applied as part of the developer or processing solution, or it can be applied after processing. The coloring fluid can also be applied to imaged precursors that are designed for either off-press or on-press development.

Abstract: A development device (100) for printing plates (112) includes a straight transport unit (116) adapted to transport printing plates inside the development device in a straight transport path (116), an immersed transport unit (120) adapted to transport printing plates inside the development device in an immersed path (120), and a switching element (232, 244b) adapted to switch between the straight transport unit (116) and the immersed transport unit (120).

Abstract: Lithographic printing plates can be obtained by contacting infrared radiation-imaged negative-working lithographic printing plate precursors with a processing solution having a pH less than 9 and comprising a UV photoinitiator. After this processing, the lithographic printing plate is floodwise exposed with UV radiation. Providing a UV-photoinitiator in the processing solution followed by UV exposure can increase imaging sensitivity and printing plate run-length, and reduce print background.

Abstract: A color contrast image in imaged lithographic printing precursors can be obtained by contacting the imaged precursor with a coloration solution containing a colorless form of a photochromic compound. Residual amounts of this compound attached to the oleophilic surface of the imaged precursor can be changed to its colored form when exposed to UV light. The coloration solution can be an alkaline or acidic developer or an alkaline or acidic solution used separately after development. The coloration solution can also be a gum solution.

Abstract: Negative-Working Lithographic Printing Plate Precursors can be provided with desired contrast coloration after imaging using a coloring fluid that includes a water-insoluble colorant that is soluble in a water-insoluble fatty alcohol. The coloring fluid provides an optical density change in the exposed regions of at least OD2 that is greater than the original optical density of those regions, OD1. The coloring fluid can be applied immediately after imaging and before processing, or it can be applied as part of the developer or processing solution, or it can be applied after processing. The coloring fluid can also be applied to imaged precursors that are designed for either off-press or on-press development.

Abstract: A color contrast image in imaged lithographic printing precursors can be obtained by contacting the imaged precursor with a coloration solution containing a colorless form of a photochromic compound. Residual amounts of this compound attached to the oleophilic surface of the imaged precursor can be changed to its colored form when exposed to UV light. The coloration solution can be an alkaline or acidic developer or an alkaline or acidic solution used separately after development. The coloration solution can also be a gum solution.

Abstract: Lithographic printing plates can be obtained by contacting infrared radiation-imaged negative-working lithographic printing plate precursors with a processing solution having a pH less than 9 and comprising a UV photoinitiator. After this processing, the lithographic printing plate is floodwise exposed with UV radiation. Providing a UV-photoinitiator in the processing solution followed by UV exposure can increase imaging sensitivity and printing plate run-length, and reduce print background.