A stamp-face platemaking device transports a medium holder inserted into a plate insertion portion to a printing unit. The medium holder holds a stamp face material at a center portion of a plate-like member, and has a cutout portion in one side end portion thereof. An optical sensor detects the top end portion of the medium holder on a sensor scanning line in the inserting direction, and the cutout start point and the cutout end point of the cutout portion. The size of the stamp face material in the inserting direction and/or the size of the stamp face material in a direction perpendicular to the inserting direction are set based on the positions of two of the detected end portions. When the cutout end point is detected, platemaking with the stamp face material is started. The cutout portion can have a wedge-like shape or a U-shape, or can change its positions and/or sizes.

A stamp-face platemaking device transports a medium holder inserted into a plate insertion portion to a printing unit. The medium holder holds a stamp face material at a center portion of a plate-like member, and has a cutout portion in one side end portion thereof. An optical sensor detects the top end portion of the medium holder on a sensor scanning line in the inserting direction, and the cutout start point and the cutout end point of the cutout portion. The size of the stamp face material in the inserting direction and/or the size of the stamp face material in a direction perpendicular to the inserting direction are set based on the positions of two of the detected end portions. When the cutout end point is detected, platemaking with the stamp face material is started. The cutout portion can have a wedge-like shape or a U-shape, or can change its positions and/or sizes.

Provides is a seal surface carving apparatus capable of carving a seal surface using only a single attachment irrespective of a size of a stamp. A porous impression die having a seal surface to be carved is set on a dedicated attachment, and is loaded in a seal surface carving apparatus. A fitting projection fit to a bottom portion of the impression die is formed on the attachment, and impression dice having various sizes may be set. In addition, a slit hole extending in a conveyance direction is formed in an impression die setting portion of the attachment. Impression die size determination means of the seal surface carving apparatus determines a size of the impression die by detecting a position at which the impression die blocks the slit hole.

A method of making a relief image printing element from a photosensitive printing blank is provided. A photosensitive printing blank with a laser ablatable layer disposed on at least one photocurable layer is ablated with a laser to create an in situ mask. The printing blank is then exposed to at least one source of actinic radiation through the in situ mask to selectively cross link and cure portions of the photocurable layer. Diffusion of air into the at least one photocurable layer is limited during the exposing step and preferably at least one of the type, power and incident angle of illumination of the at least one source of actinic radiation is altered during the exposure step. The resulting relief image comprises a plurality of dots and a dot shape of the plurality of dots that provide optimal print performance on various substrates, including corrugated board.

The present disclosure is directed to a thermal developing assembly that is configured to reduce (or eliminate) the reactivity of contaminants and/or unreacted photosensitive material associated with forming a relief image on a photosensitive printing element during thermal development. The thermal developing assembly is configured to reduce (or eliminate) the reactivity of a byproduct associated with forming a relief image on a photosensitive printing element, the byproduct including but not limited to, contaminants within vapors (e.g., fumes), contaminants within condensate, unreacted photosensitive material, and combinations thereof.

The present disclosure is directed to a thermal developing assembly that is configured to reduce (or eliminate) the reactivity of contaminants and/or unreacted photosensitive material associated with forming a relief image on a photosensitive printing element during thermal development. The thermal developing assembly is configured to reduce (or eliminate) the reactivity of a byproduct associated with forming a relief image on a photosensitive printing element, the byproduct including but not limited to, contaminants within vapors (e.g., fumes), contaminants within condensate, unreacted photosensitive material, and combinations thereof.

A method of thermal development of flexographic printing elements, having steps of: fixing a relief precursor a movable support; repeatedly moving the support in a multitude of movement cycles; heating the relief precursor to a temperature sufficient to cause the uncured portions of the photopolymer layer to soften or liquefy; contacting with a development medium; Single movement cycles are carried out with different heating powers and different contacting with the developing medium such that one may improve the registration accuracy of the printing element, ease removal of functional layers, smoothen the relief plate precursor surface, and address heat build-up problem.

A method of thermal development of flexographic printing elements, having steps of: fixing a relief precursor a movable support; repeatedly moving the support in a multitude of movement cycles; heating the relief precursor to a temperature sufficient to cause the uncured portions of the photopolymer layer to soften or liquefy; contacting with a development medium; Single movement cycles are carried out with different heating powers and different contacting with the developing medium such that one may improve the registration accuracy of the printing element, ease removal of functional layers, smoothen the relief plate precursor surface, and address heat build-up problem.

The present disclosure is directed to a thermal developing assembly that is configured to reduce (or eliminate) the reactivity of contaminants and/or unreacted photosensitive material associated with forming a relief image on a photosensitive printing element during thermal development. The thermal developing assembly is configured to reduce (or eliminate) the reactivity of a byproduct associated with forming a relief image on a photosensitive printing element, the byproduct including but not limited to, contaminants within vapors (e.g., fumes), contaminants within condensate, unreacted photosensitive material, and combinations thereof.

The present disclosure is directed to a thermal developing assembly that is configured to reduce (or eliminate) the reactivity of contaminants and/or unreacted photosensitive material associated with forming a relief image on a photosensitive printing element during thermal development. The thermal developing assembly is configured to reduce (or eliminate) the reactivity of a byproduct associated with forming a relief image on a photosensitive printing element, the byproduct including but not limited to, contaminants within vapors (e.g., fumes), contaminants within condensate, unreacted photosensitive material, and combinations thereof.