Some examples include checking the quality of printed products that are consecutively produced by multiple printing presses to have at least three printed patterns spaced apart from one another. The printed patterns are printed using different printing processes, such as a steel engraving process, an offset printing process, and a screen printing process that may be used for printing the three printed patterns of each printed product. A screen printing press is used for the screen printing process, with multiple steel plates being alternately used in the same production operation for the steel engraving process in an intaglio printing press. For at least two of the steel plates involved in carrying out the steel engraving process, a processing unit may selectively ascertain the deviation of the respective value of the relevant distances associated with the printed patterns, which may be instantaneously ascertained from a defined scale.

There is described a method for manufacturing intaglio printing plates for the production of security papers, wherein a laser beam (2) is used to engrave intaglio printing patterns (3, 3.1, 3.2, 3.3) directly into the surface of a laser-engravable, especially metallic, printing plate medium (1), wherein laser engraving of the printing plate medium (1) is carried out layer by layer in several individual engraving steps performed one after the other in register so that the intaglio printing patterns (3, 3.1, 3.2, 3.3) are gradually engraved into the surface of the printing plate medium (1) up to desired engraving depths, the surface of the engraved printing plate medium (1) being cleaned from residues of the laser engraving process following and between each individual engraving step.

Some examples include checking the quality of printed products that are consecutively produced by multiple printing presses to have at least three printed patterns spaced apart from one another. The printed patterns are printed using different printing processes, such as a steel engraving process, an offset printing process, and a screen printing process that may be used for printing the three printed patterns of each printed product. A screen printing press is used for the screen printing process, with multiple steel plates being alternately used in the same production operation for the steel engraving process in an intaglio printing press. For at least two of the steel plates involved in carrying out the steel engraving process, a processing unit may selectively ascertain the deviation of the respective value of the relevant distances associated with the printed patterns, which may be instantaneously ascertained from a defined scale.

A halftone raster image, suitable for rendering a continuous-tone image, which comprises a plurality of regularly tiled spiral dots. Said spiral dots comprise (i) image pixels arranged as a first arc (200) or as a plurality of arcs which together represent a first spiral (100), and (ii) non-image pixels arranged as a second arc (201) or as a plurality of arcs which together represent a second spiral (101), wherein neighbour halftone dots from said plurality of regularly tiled halftone dots represent a double spiral or triple spiral.

A printing intaglio (100A), (100B) is a printing intaglio for use in intaglio printing, the printing intaglio having a surface which has a plurality of first recessed portions (12) that form a pattern to be printed, wherein at least one of the plurality of first recessed portions has a plurality of minute recessed portions (16p) inside the first recessed portion, and when viewed in a direction normal to the surface of the printing intaglio, a two-dimensional size of the plurality of minute recessed portions is not less than 10 nm and less than 500 nm.

According to a first aspect of the invention, there is provided a method of processing a printing body, the printing body comprising a substrate and a diamond-like carbon (DLC) layer on the substrate, the method comprising engraving a printing pattern into the DLC layer. This method is advantageous, as it reduces the number of process steps required in processing the printing body, and reduces the loss of fine detail in the printing pattern.

Provided is a fully automatic gravure plate-making processing system capable of manufacturing a gravure plate-making roll more quickly as compared to a conventional case, achieving space saving, performing an unattended operation even in the nighttime, and reducing dust between individual processes. The fully automatic gravure plate-making processing system includes: a first industrial robot for chucking and handling an unprocessed plate-making roll; a second industrial robot for chucking and handling the unprocessed plate-making roll; a roll stock apparatus, a photosensitive film coating apparatus, a laser exposure apparatus, an ultrasonic cleaning apparatus with a drying function, a grinding wheel polishing apparatus, and a paper polishing apparatus, which serve as processing apparatus arranged in a handling area of the first industrial robot; and a degreasing apparatus, a copper plating apparatus, a developing apparatus, an etching apparatus, a resist removal apparatus, a surface hardening film forming apparatus, and an ultrasonic cleaning apparatus, which serve as processing apparatus arranged in a handling area of the second industrial robot, to thereby perform plate-making processing.

A gravure printing roll that enables printing of fine dots with a size close to that of cells and enables printing on a print subject, such as a printing substrate, without changing the appearance of the print subject. The gravure printing roll includes: a gravure printing roll body; and cells formed in a peripheral surface of the gravure printing roll body. Each of the cells has an opening with a ratio between a dimension in a circumferential direction of the gravure printing roll body and a dimension in an axial center direction of the gravure printing roll body (dimension in the circumferential direction/dimension in the axial center direction) being 1.15 to 7, and have an opening area of 3900 m.sup.2 or smaller.

A halftone raster image, suitable for rendering a continuous-tone image, which comprises a plurality of regularly tiled spiral dots. Said spiral dots comprise (i) image pixels arranged as a first arc (200) or as a plurality of arcs which together represent a first spiral (100), and (ii) non-image pixels arranged as a second arc (201) or as a plurality of arcs which together represent a second spiral (101), wherein neighbour halftone dots from said plurality of regularly tiled halftone dots represent a double spiral or triple spiral.

A rotogravure printing machine has a shaft that rotates and a rotogravure cylinder sleeve for rotation with the shaft. An annular end plate connects to the shaft, and the end plate has a contact surface for contact with a mating contact surface at an inner side of the cylinder sleeve.