An object of the present invention is to provide a lithographic printing plate precursor from which a lithographic printing plate with excellent oil-based cleaner printing durability is obtained, a method of producing a lithographic printing plate, a printing method, and a method of producing an aluminum support. The lithographic printing plate precursor of the present invention is a lithographic printing plate precursor including an aluminum support, and an image recording layer disposed on the aluminum support, in which the aluminum support includes an aluminum plate and an anodized aluminum film disposed on the aluminum plate, the image recording layer is disposed on the aluminum support on a side of the anodized film, and an area ratio of projections with a height of 0.80 μm or greater from an average level, which is obtained by measuring a surface of the aluminum support on a side of the image recording layer in an area of 400 μm×400 μm using a non-contact three-dimensional roughness meter, is 20% or less.

According to aspects of the embodiments, there is provided a method of measuring the amount of fountain solution employed in a digital offset lithography printing system. Fountain solution thickness is measured using a glass roll at a lower temperature than the fountain solution. The lower temperature causes the fountain solution to undergo a change in state and in a solid state the fountain solution crystalizes and changes roll opacity with the thickness of the film. When radiated with a light source the opacity is continuously measured through the surface of the roller. The thickness of the crystallized fountain solution can then be determined via the opacity level increase by the crystallization and the impact to the opacity on the glass roll.

According to aspects of the embodiments, there is provided a method of measuring the amount of fountain solution employed in a digital offset lithography printing system. Fountain solution thickness is measured using a glass roll at a lower temperature than the fountain solution. The lower temperature causes the fountain solution to undergo a change in state and in a solid state the fountain solution crystalizes and changes roll opacity with the thickness of the film. When radiated with a light source the opacity is continuously measured through the surface of the roller. The thickness of the crystallized fountain solution can then be determined via the opacity level increase by the crystallization and the impact to the opacity on the glass roll.

According to aspects of the embodiments, there is provided a method of determining the amount of fountain solution employed in a digital offset lithography printing system. Fountain solution thickness is determined by examining optical density of some halftone or solid patch versus laser current level. The apparatus and method uses a variable current signal to dither or perturb the laser imaging system to irradiate a fountain solution layer to create patches at different laser current levels. An aptly programmed controller then process optical density measurements to indirectly estimate fountain solution level.

According to aspects of the embodiments, there is provided a method of determining the amount of fountain solution employed in a digital offset lithography printing system. Fountain solution thickness is determined by examining optical density of some halftone or solid patch versus laser current level. The apparatus and method uses a variable current signal to dither or perturb the laser imaging system to irradiate a fountain solution layer to create patches at different laser current levels. An aptly programmed controller then process optical density measurements to indirectly estimate fountain solution level.

An optical light reflectance measurement system above an imaging member surface measures fountain solution surface light reflectance interference on reflective substrate portions of the imaging member surface in real-time during a printing operation. The measured light reflectance interference corresponds to a thickness of the fountain solution layer and may be used in a feedback loop to actively control fountain solution layer thickness by adjusting the volumetric feed rate of fountain solution added onto the imaging member surface during a printing operation to reach a desired uniform thickness for the printing. This fountain solution monitoring system may be fully automated.

An optical light reflectance measurement system above an imaging member surface measures fountain solution surface light reflectance interference on reflective substrate portions of the imaging member surface in real-time during a printing operation. The measured light reflectance interference corresponds to a thickness of the fountain solution layer and may be used in a feedback loop to actively control fountain solution layer thickness by adjusting the volumetric feed rate of fountain solution added onto the imaging member surface during a printing operation to reach a desired uniform thickness for the printing. This fountain solution monitoring system may be fully automated.

A multilayer imaging blanket for a variable data lithography system, including a multilayer base including a sulfur-containing layer; and a cured topcoat layer including a polyurethane in contact with the sulfur-containing layer of the multilayer base.

A multilayer imaging blanket for a variable data lithography system, including a multilayer base including a sulfur-containing layer; and a cured topcoat layer including a polyurethane in contact with the sulfur-containing layer of the multilayer base.

A dampening fluid deposition system includes a vapor generator adjacent an air supply channel and in fluid communication with a dampening fluid supply to produce dampening fluid vapor. The vapor generator includes a vapor channel having an interior in communication with air confined within the air supply channel. The vapor generator may include a liquid reservoir receiving dampening fluid from the dampening fluid supply and a heater that heats the received dampening fluid into dampening fluid vapor. The liquid reservoir may include a wick that stores dampening fluid and releases dampening fluid vapor into the vapor channel and a heat conductive tub that holds the wick and dampening fluid. The passive dampening fluid deposition system mixes the dampening fluid vapor with the confined air to form an air/vapor mix that is condensed as a layer of dampening fluid onto the reimageable surface of an imaging member.