EP1119457B2 - Gravure plate and gravure process for full printing of large surfaces - Google Patents

Description

The invention relates to a printing plate for full-surface printing of large areas in intaglio printing, a process for the preparation of the printing plate and a method for producing a data carrier with a large-scale printed image produced by intaglio printing.

In intaglio printing, it is known to produce two-dimensional representations through closely spaced engraving lines, the individual engraving lines generally being fractions of a millimeter wide and separated from each other by ungravelled webs.

For the printing process, the engraving lines of the printing plate are filled with paint. The excess ink is removed from the printing plate with the help of a wiping cylinder or a doctor blade so that the engraving lines are filled to the brim with color. At the same time, the separating webs provided between the engraving lines are cleaned in this operation.

During the printing process, the printing medium, which is usually paper, is finally pressed onto the printing plate with high pressure by means of a pressure cylinder having an elastic surface. The disk is thereby pressed into the filled with color engraving lines of the printing plate and thus comes into contact with the ink. When removing the disk, this pulls the ink out of the recesses of the engraving lines. The printed image produced in this way has printing lines which vary depending on the depth of the engraving in the ink layer thickness.

If lithographic printing inks are used in intaglio printing, then when printing on a white data carrier with low ink layer thicknesses, bright shades are obtained, while when printing with thick layers of ink, darker shades are obtained.

In comparison with other common printing processes, the intaglio printing process can produce print images with very large ink layer thicknesses. The resulting printed images are even manually felt when using correspondingly deep engravings. By using correspondingly fine engravings, in contrast, extremely fine, pin sharp printing lines are also possible.

Although very high-quality printed images resolved in line structures can be produced by intaglio printing, it has the disadvantage that larger continuous printing areas, i. Lines with a width of about one millimeter and more can not be produced. This is due to the fact that when wiping the inked printing plate in the area of large-scale engraving not only the excess color is removed, but also color from the engraving. As a result, the ink surface is lowered below the surface level of the printing plate in these engraving areas. Since the paper pressed into the engraved areas of the printing plate does not reach the color surface at all points, gaps are created in the printed image which render the printing useless.

Object of the present invention is therefore to provide measures that allow large-scale print image areas in the intaglio printing process over the entire area to print so that the viewer is a uniform color impression is generated.

This object is achieved by the features of the independent claims. Further developments can be found in the dependent claims.

The invention is based on the recognition that when wiping the printing cylinder or the printing plate disturbing wiping of ink from the field of engraving can be prevented if so-called dividers are provided in the engraving, the action of the wiping cylinder on the engraving Prevent the printing plate introduced ink or keep it as low as possible. It is presumed that the wave of excess pressure ink which has been pushed out of the wiping cylinder by the wiping cylinder over the surface of the printing plate also pulls out portions of color from the engraving due to hydrodynamic effects. The dividers apparently prevent the ink located in the engraving moves in the total volume and is pulled along with the color of the wiper cylinder. The dividers thus subdivide a larger area engraving in adjacent "chambers" or channels, although allow during printing printing removal of the ink perpendicular to the printing plate surface, but not during the wiping process parallel to the printing plate surface.

The dividers are preferably arranged transversely to the direction of rotation of the printing cylinder. In this arrangement, during the wiping process, they apparently cause a shearing off of the ink fountain and thus a hydrodynamic decoupling of the ink in the engraving from the wiping process taking place on the printing plate surface.

In cases where it is not possible to dispose the separating webs transversely to the wiping direction, the separating webs effect at least a subdivision of the large-area engravings and give them a functionality which is similar with respect to the wiping of paint, as exists in finely structured engravings.

Taking into account the basic idea according to the invention in an optimized form, the engraving areas are preferably to be equipped with separating webs transversely to the wiping direction. For engraving lines that run along the wiping direction, this results in a subdivision of the engraving lines in juxtaposed subsections. The engraving extending transversely or diagonally to the wiping direction is subdivided at least in the longitudinal direction of the engraving line, wherein the separating webs preferably extend parallel to the engraving edges.

In cases where the engraving consists not only of very wide engraving lines, but also contains large-scale engraving elements which have similar expansions in the x and y directions, it is also possible to carry out the dividers in a grid shape, ie to provide intersecting dividers, which, for example, extend longitudinally and transversely with respect to the wiping direction. It is also possible to provide dividers in the form of concentric circles honeycomb or the like. Such a design of the dividers not only has the advantage that the function of the dividers is guaranteed regardless of the wiping direction in each case, it also ensures that the dividers receive increased mechanical stability.

The provision according to the invention of separating webs in the engraving of the intaglio printing plate already proves to be particularly advantageous from an engraving line width greater than 0.5 mm. For engraving lines with a width of 1 mm and more, they prove to be almost essential.

The height of the dividers can, as experiments showed, be varied in a relatively wide range. If the dividing webs end at the level of the printing plate surface, it must be ensured that the dividing web form viewed in cross section tapers in a wedge shape. This ensures that on the one hand the subdivision of the engraving into separate channels or chambers takes place in an optimal form, on the other hand, however, the sharp-edged dividers have no interruption of the printing surface result.

If the separating web upper edges are lowered below the level of the printing plate surface, the cross-sectional shape of the separating webs can deviate almost arbitrarily from the wedge shape, i. trapezoidal, rounded or otherwise designed, but only wedge-shaped tapered dividing web forms are patent. Since the upper edge of the separating webs is always arranged below the level of the printing plate surface in this case and thus always covered with ink, the generation of a continuous printing surface is ensured in each case.

It has been shown that when using dividers whose top ends exactly at the level of the printing plate surface, the surface of the wiping cylinder is worn relatively quickly. A lowering of the separating web upper edge by at least 2 μm to 5 μm eliminates this problem. For this reason, such a minimum reduction is recommended in any case.

Experiments have also shown that a much greater reduction of Trennstegoberkanten is possible. Accordingly, based on the engraving depth, a reduction to about 50% below the level of the printing plate surface is possible.

It has also been found that the dividing webs, insofar as they have a height, referred to below as the amplitude, of more than 50% in relation to the engraving depth produce "notches" in the ink layer surface on the printing surface produced therewith. Although the printing surface produced with such a large-scale engraving is printed continuously with color, it thus has a surface relief, which originates from the separating webs. The surface relief is particularly strong when the separation pad amplitude is selected in the range of 75% to 100% of the engraving depth. At lower amplitudes, e.g. in the range of about 60%, this surface relief becomes weaker and weaker until it finally disappears completely at an amplitude of about 50%. If the value falls below 50%, especially with deeper engravings, printing errors in the form of gaps or dropouts are increasingly likely to render printing useless.

Based on the experiments finally showed that engraving depths of 5 microns to about 150 microns are outstandingly useful in the invention. As a preferred engraving depth turned out for the production of common printed images, the range of 10 .mu.m to 60 .mu.m. When using conventional intaglio printing inks one thus obtains color layers with a rather glazed color impression and even slight changes in the engraving depth lead to visually perceptible changes in hue. Engraving with a depth in the range of about 60 microns to 100 microns are particularly suitable for printing color layers with a saturated, opaque color impression. Of course, the exact values vary, depending on whether the color is light or dark.

Engravings with a depth of 100 microns and more are particularly suitable for the production of color layer structures with a well-perceived with the sense of touch relief.

The finer the fine structure of the printed surface represented by the surface relief, the less it appears when viewed without tools (magnifying glass). This is true at least for fine structures that are due to dividers with a distance of about 20 microns to 150 microns and wedge-shaped dividing web shape. Dividers with a distance of 150 μm to approx. 400 μm are already recognizable with the unaided eye, but in no way disturb the overall impression of the printed color surface. If a trapezoidal cross-sectional profile is used instead of the wedge-shaped, tapered separating webs according to the invention, the notches present in the surface relief become wider, ie. scale. With such structures, a design influence on the surface to be printed is possible by e.g. the grid formed by the dividers also appears as a design element in appearance. If the dividers are not grid-like, but incorporated in the form of characters, icons or the like in the engraving and these characters or symbols in the printed area can be seen.

Increasing the separation distance significantly above 500 microns, increasingly occur at the aforementioned printing errors in the form of blemishes, dropouts, stains or the like.

Considering that the production of intaglio printing plates is already one of the most expensive methods for the production of printing plates, it is also easy to understand that the additional provision of dividers in the engraving raises quite considerable additional problems. This is all the more so because not only the shape, amplitude and arrangement of the separating webs, but also a precision in the micrometer range is necessary for the inventive function. Manually or by etching such printing plates are not produced. The prints and printing plates according to the invention therefore ensure a high degree of security against counterfeiting and imitation.

However, the production of such printing plates is possible by an engraver of the Applicant, as shown in the WO 97/48555 is described. With this device, the possibility is given to mill intaglio printing plates computer-controlled. For this, the lines of a two-dimensional line drawing are captured by means of a computer and the areas of each individual line are defined exactly. With an engraving tool, eg a rotating stylus or a laser beam, the outer contour of these surfaces is first engraved in order to surround the surface cleanly. Subsequently, the bordered area of the area is cleared out by means of the same or another engraving tool, so that the entire line is exactly engraved in accordance with the line template. Depending on the type and guidance of the engraving tool, both a certain roughness (instead of a smooth surface) can be generated at the base of the engraving, as well as the separating webs according to the invention having any desired amplitude, flank angle or precisely predetermined cross-sectional shape. It is important, as already mentioned, that for the function according to the invention, the partitions should have a minimum amplitude of about 50% of the engraving depth. If this value falls well below the ink adheres to the bottom of the engraving better than smooth engraving reason, but with large-scale engraving elements, the printing errors mentioned above can not be avoided.

With the invention completely new possibilities in the design of intaglio printing plates are offered. It is now also possible to produce engraving lines with a width of 1 mm to 10 mm and more by using large-area printing engravings and this with ink layer thicknesses of 40 microns and more. Likewise, continuous geometric surfaces of a few square centimeters in size can be implemented without problems in intaglio printing.

The fine structure of the printing surface can be present both in the form of a grid and in the form of written or pictorial symbols. Even if the coarsest fine structure (separation pitch in the order of 500 microns) is selected, this can be imitated by any known printing method, whereby the security against forgery of the corresponding printed data carriers is significantly increased. The fine structure thus not only demonstrates the use of the inherently high-quality intaglio printing method, but also the use of the in the WO 97/48555 described engraving device that is due to high costs no counterfeiter available.

Fig. 1 bis 6

jeweils einen Ausschnitt einer Druckplatte mit einer Gravur im Querschnitt.

Further advantages will become apparent from the description of the following embodiments. Show it:

Fig. 1 to 6

each a section of a printing plate with an engraving in cross section.

Fig. 1 shows a section of a printing plate 1, the surface 2 is provided with an engraving 3 predetermined depth t, which serves to receive ink. The engravings shown in cross section are linear, perpendicular to the plane of the paper and are formed so that between the parallel grooves depressions 4 are present, the upper edge 5 is at the level of the printing plate surface 2. On the one hand, the separating webs 4 prevent the ink from being removed from the depressions formed by the engraving 3 and, on the other hand, cause a structuring of the ink layer transferred to a substrate. The substrate is printed area-wide with color in the area of the engraving.

The offset with which the parallel engraving 3 are generated corresponds to the distance d of Trennstegoberkanten 5. For in the Fig. 1 to 3 In the case illustrated, in which the offset of the engraving tool during the engraving of the depressions 3 corresponds to the separating web upper edge distance d, the distance d is preferably in the range from 20 .mu.m to 150 .mu.m, with a spacing of approximately 50 .mu.m for the production of fine structure not recognizable without auxiliary means is particularly preferred.

The modulation of the ink layer thickness produced by the separating webs produces a fine structure in the printed ink layer which, under normal observation, is not resolved with the naked eye and can therefore serve as a hidden security feature that can not be reproduced either electrophotographically or with other printing processes.

Despite the fine structuring of the printed ink layer, a homogeneous color impression is produced for the human eye. The intensity of the color impression or the perceived hue depend on the average ink layer thickness and can be adjusted by the engraving depth t at a given flank angle α.

In Fig. 2 a printing plate is shown in cross-section, with a medium thinner ink layer can be printed, which produces a lighter hue. The engraved areas of in Fig. 1 and 2 illustrated printing plates are the same size and the engravings 3 have the same flank angle α. Due to the in Fig. 2 lower engraving depth t is chosen a smaller distance d for the offset of the engraving lines. For the printing of cohesive color areas is essential that, taking into account the flank angle α, the engraving depth t and the distance d of Trennstegoberkanten 5 are selected so that within a engraved area on the level of the printing plate surface 2 no flat plateaus.

In Fig. 3 the engraved area has the same extent as in the examples of Fig. 1 and 2 , The engraving depth t is the same as in Fig. 1 , Although the separating webs 4 have a different flank angle β, one with a pressure plate according to FIG Fig. 3 transferred color layer on the same average layer thickness, as one with a printing plate according to Fig. 1 printed. Despite different distance d of the dividers 5 and thus different fine structure, are with the pressure plates of the Fig. 1 and 3 Surfaces printed in the same color.

The printing plates according to the FIGS. 2 and 3 On the other hand, they have the same separating web spacing d, thereby producing a fine structure of the same periodicity, but due to the different flank angles (.alpha., .beta.), lead to ink layers of different average thickness and different tints.

The engravings 3 are preferably produced with rotating styli whose point angle, measured to the center line of the stylus, corresponds to the flank angle of the engraving. The flank angles are preferably in the range of 15 ° to 60 °, particularly preferred is the range of 30 ° to 50 °. In particular with the preferred point angles, mechanical engraving tools have an increased service life. Printing plates with the preferred flank angles are easier to duplicate by impression techniques and also have particularly favorable printing properties. As a separating web shape (cross section), wedge-shaped geometries are used. However, any other, in particular wave or sinusoidal geometries are conceivable, but only wedge-shaped tapered dividing web forms are according to the patent. The shape of the cross section of the partitions 4 is limited only by the design possibilities of the contour of an engraving tool.

If the ink layer thickness is to be reduced in the transition region from one fine structure line to the adjacent one only to a value other than zero, suitable structures are those described in US Pat 4 and 5 are shown.

A printing plate according to Fig. 4 is produced by removing the outwardly-facing ends of the dividers after engraving the recesses forming the fine-structure. Alternatively, the entire area to be provided with an engraving can first be cleared away in the depth a and then the depressions forming the fine structure can be engraved. The outwardly facing ends of the dividers are thereby lowered by the value a below the level of the printing plate surface 2. The remaining height of the separating webs is referred to below as the amplitude b and results from the difference between the engraving depth t and separating web lowering a. A printed with such a printing plate substrate is provided in the area of the engraving area-wide with a color layer of thickness a, which is additionally modulated with a fine structure of maximum amplitude b. The plateau in this example formed upper ends of the dividers produce fine bright lines in the printed image. With appropriate guidance of the dividing lines 4 generating engraving lines generated by the trapezoidal dividers 4 in the printed image bright lines pattern, font or icon reflect.

According to the in Fig. 5 In the embodiment shown, a separating web lowering a can also be achieved by selecting the offset between the individual engraving lines to be so small at a given flank angle α and given engraving depth t that the separating web top edge 5 lies below the level of the printing plate surface 2.

A dividing web lowering is advantageous because the plastic surface of the wiping cylinder does not come into direct contact with the sharp-edged dividing webs 4 thereby reducing wear and tear on the wiping cylinder surface as well as on the fine engraved structures of the printing plate. The separating web drop a is preferably 2 μm to 5 μm below the level of the printing plate surface 2. In order to ensure a clean reproduction of the engraving as a fine structure of the transferred ink layer, the amplitude b should be more than 50% of the engraving depth t.

Fig. 6 shows a variant of the invention, supplemented with dividers engraving. In this embodiment, the partitions 4 are arranged at a greater distance d. In contrast to the embodiments of the Fig. 1 to 5 The separating web distance d here does not correspond to the offset of the engraving tool during the engraving of the depressions. Preferably, the distance d is less than 500 μm. Between the dividers 4 horizontal bottom surfaces 6 of the engraving are provided, which have a specifically set surface roughness to improve the ink adhesion. The adjustment of the surface roughness is made by selecting the geometry of the point angle and tip radius of the engraving tool and by specifying suitable values for the offset between two engraving lines transverse to the engraving direction.

According to a preferred embodiment of the invention, the engraving 3 is introduced into a printing plate surface 2 such that the engraving depth within the engraved surface is not constant, but continuously increases or decreases in one direction (FIGS. 7a, 7b). The variation of the engraving depth is preferably such that the lowest points of each engraving line lie on a plane inclined to the printing plate surface. It is also possible to change the engraving depth so that the lowest points lying in a cross-sectional plane of the printing plate lie on a curved curve whose course can be described, for example, by a parabola hyperbola. The gravure depth variation can be used to vary the perceived hue within a contiguously printed color area, in particular if the depth variation is between 5 μm and 60 μm.

In the embodiment according to Fig. 6a is the separation distance d and the height of the dividers throughout the engraving constant, while in the variant of FIG. 76b increase distance and height of the dividers with the engraving depth (d ₁ > d ₂ ).

It is possible to combine on a printing plate engravings of different types and designs as well as with different dividing web shapes. It is also conceivable to make surfaces with different engraving types or dividing web shapes adjoin one another as well as to make corresponding variations within a closed engraved surface. Furthermore, a second engraving may be superimposed on a first engraving. If the first engraving of parallel, preferably straight engraving lines formed and the second engraving also of parallel, preferably straight engraving lines, creates a so-called cross-line grid. Form the lines of the first and second engraving to each other an angle between 20 ° and 90 °, in particular from 40 ° to 70 °, the resulting engraving has a particularly good ink adhesion, which has a favorable effect on the printing properties of a corresponding engraved printing plate , The printed color layers also have a particularly uniform hue.

The first and the superimposed second engraving can be produced with engraving tools of different geometry as well as with different engraving depth and / or different engraving line offset. In the case of the preferred cross-grid, this leads to periodically interrupted dividers.

Claims (68)

1. An intaglio printing plate (1) for all-over printing of contiguous printed image areas, the printed image being incorporated into the printing plate surface (2) in the form of an engraving (3), characterized in that partitions (4) are provided in the engraved, ink-receiving areas so as to divide said engraved areas into partial areas, said partitions (4) being designed so as not to have any areas at the level of the printing plate surface, and the ratio (b:t) between partition height (b) and engraving depth (t) being in the range of 0.5 to 1, the form of the partitions tapering in a wedge shape, viewed in cross section.
2. A printing plate according to claim 1, characterized in that the engraved areas are engraved lines and/or large-area engraved elements.
3. A printing plate according to claim 2, characterized in that the engraved lines are wider than 0.5 millimeters, preferably wider than 1.0 millimeter.
4. A printing plate according to any of claims 1 to 3, characterized in that the engraved areas are engraved lines, and the partitions (4) extend transversely to the engraved line so as to form adjacent partial portions, and the partitions (4) extend transversely or diagonally to the wiping direction.
5. A printing plate according to any of claims 1 to 3, characterized in that the engraved areas are engraved lines, and the partitions extend parallel to the engraved line and transversely or diagonally to the wiping direction.
6. A printing plate according to claim 1, characterized in that the partitions (4) are disposed in the engraved area so as to form a uniform fine structure in the form of a screen or regular pattern.
7. A printing plate according to claim 6, characterized in that the screen is a line screen or cross-line screen.
8. A printing plate according to claim 7, characterized in that the cross-line screen consists of a first engraving with parallel, preferably straight, engraved lines and a second engraving with parallel, preferably straight, engraved lines superimposed on the first engraving.
9. A printing plate according to claim 8, characterized in that the lines of the first and second engravings form with each other an angle between 20° and 90°, in particular 40° to 70°.
10. A printing plate according to any of claims 1 to 9, characterized in that the upper edges of the partitions (4) are disposed at a mutual distance (d) which is greater than or equal to the contact width of an engraving tool used for engraving the engraved area.
11. A printing plate according to any of claims 1 to 10, characterized in that the mutual distance (d) of the upper edges (5) of the partitions is smaller than 500 microns.
12. A printing plate according to claim 11, characterized in that the mutual distance (d) of the upper edges (5) of the partitions (4) is 20 microns to 150 microns.
13. A printing plate according to claim 12, characterized in that the mutual distance (d) of the upper edges (5) of the partitions (4) is 50 microns.
14. A printing plate according to any of claims 1 to 13, characterized in that the upper edges (5) of the partitions (4) have a lowering (a) of at least 2 microns to 5 microns over the printing plate surface (2).
15. A printing plate according to any of claims 1 to 14, characterized in that the partitions (4) have a partition height (b) in the range of 3 microns to 150 microns.
16. A printing plate according to claim 15, characterized in that the partition height (b) is in the range of 8 microns to 60 microns.
17. A printing plate according to any of claims 1 to 16, characterized in that the engraving depth (t) is between 5 microns and 150 microns.
18. A printing plate according to claim 17, characterized in that the engraving depth (t) is between 10 microns and 60 microns.
19. A printing plate according to any of claims 1 to 18, characterized in that the partitions (4) have flanks with flank angles (α) in the range of 15° to 60° based on the perpendicular to the printing plate surface (2).
20. A printing plate according to claim 19, characterized in that the partitions (4) have flanks with flank angles (α) in the range of 30° to 50°.
21. A printing plate according to any of claims 1 to 20, characterized in that the partitions (4) form a linear fine structure through their parallel arrangement.
22. A printing plate according to claim 21, characterized in that the printing plate (1) is adapted for use with a printing cylinder such that the linear fine structure is substantially parallel to the rotation axis of the printing cylinder.
23. A printing plate according to any of claims 1 to 22, characterized in that both the length and the width of the engraved area are more than one millimeter.
24. A printing plate according to any of claims 1 to 23, characterized in that at least a first engraved area and a second engraved area are provided which differ by different designs of the partitions (4) and/or partition arrangements.
25. A printing plate according to claim 24, characterized in that the partitions (4) in the first engraved area have a different orientation from the partitions (4) in the second engraved area.
26. A printing plate according to claim 25, characterized in that the partitions (4) in the first engraved area are aligned at right angles to the partitions (4) in the second engraved area.
27. A printing plate according to any of claims 24 to 26, characterized in that the first engraved area has a different engraving depth (t) from the second engraved area.
28. A printing plate according to any of claims 24 to 27, characterized in that the upper edges (5) of the partitions in the first engraved area have a greater mutual distance (d) than the upper edges (5) of the partitions in the second engraved area.
29. A printing plate according to any of claims 24 to 28, characterized in that the upper edges (5) of the partitions in the second engraved area have a greater distance (a) from the printing plate surface (2) than the upper edges (5) of the partitions in the first engraved area.
30. A printing plate according to any of claims 24 to 29, characterized in that the first and second engraved areas adjoin each other.
31. A method for producing a data carrier with a printed image produced by the intaglio printing process and comprising at least one printed image area having an ink layer and a surface area of more than one square millimeter, the ink layer covering the complete printed image area, the lateral dimensions such as length and width of the area being greater than 0.5 millimeters, and the ink layer having along one direction at least one notch on which the ink layer thickness passes through a minimum, using an intaglio printing plate (1) according to claim 1.
32. A method according to claim 31, characterized in that the lateral dimensions such as length and width of the area are greater than one millimeter.
33. A method according to claim 31 or 32, characterized by a surface relief of the ink layer, the surface relief having a fine structure with regularly recurring structural elements.
34. A method according to claim 33, characterized in that the structural elements recur at a distance smaller than 0.5 millimeters.
35. A method according to claim 33 or 34, characterized in that the fine structure forms a screen or regular pattern.
36. A method according to claim 35, characterized in that the screen is a line screen or cross-line screen.
37. A method according to claim 35 or 36, characterized in that the fine structure forms a screen wherein the line width is less than 150 microns.
38. A method according to any of claims 33 to 37, characterized by at least a first printed image area with a first fine structure and a second printed image area with a second fine structure different from the first fine structure.
39. A method according to claim 38, characterized in that the first and second printed image areas represent one or more characters or a picture.
40. A method according to claim 38 or 39, characterized in that the fine structure of the first printed image area has a different orientation from the fine structure of the second printed image area.
41. A method according to any of claims 38 to 40, characterized in that the fine structures of the first and the second printed image areas differ by different line widths.
42. A method according to any of claims 38 to 41, characterized in that the first and second printed image areas differ by different ink layer thicknesses.
43. A method for producing an intaglio printing plate (1) for all-over printing of a large area by the intaglio printing process comprising the steps of:

    - providing a printing plate with a printing plate surface (2), and

    - engraving at least one engraved area corresponding to the large area to be printed into the printing plate surface (2) with an engraving tool such that leave partitions (4) are left that rise up in the engraved area and divide the engraved area into partial areas, the ratio (b:t) between partition height (b) and engraving depth (t) being in the range of 0.5 to 1, and that the partitions (4) are designed by the engraving so as to taper in a wedge shape, viewed in cross section, and not to have any areas at the level of the printing plate surface (2).
44. A method according to claim 44, characterized in that the engraved areas are engraved as engraved lines and/or large-area engraved elements.
45. A method according to claim 45, characterized in that the engraved lines are wider than 0.5 millimeters, preferably wider than 1.0 millimeter.
46. A method according to any of claims 44 to 46, characterized in that the engraved areas are engraved as engraved lines, and the partitions (4) extend transversely to the engraved line so as to form adjacent partial portions, and the partitions extend transversely or diagonally to the wiping direction.
47. A method according to any of claims 44 to 46, characterized in that the engraved areas are engraved as engraved lines, and the partitions are formed parallel to the engraved line and extend transversely or diagonally to the wiping direction.
48. A method according to claim 44, characterized in that the partitions (4) form a uniform fine structure in the form of a screen or regular pattern.
49. A method according to claim 49, characterized in that the screen is a line screen, dot screen or cross-line screen.
50. A method according to claim 50, characterized in that the cross-line screen is formed of a first engraving with parallel, preferably straight, engraved lines and a second engraving with parallel, preferably straight, engraved lines superimposed on the first engraving.
51. A method according to claim 51, characterized in that the lines of the first and second engravings form with each other an angle between 20° and 90°, in particular 40° to 70°.
52. A method according to any of claims 44 to 50, characterized in that the partitions (4) are produced with flank angles (α) in the range of 15° to 60° based on the perpendicular to the printing plate surface (2).
53. A method according to claim 53, characterized in that the partitions are produced with flank angles (α) in the range of 30° to 50°.
54. A method according to claim 53 or 54, characterized in that an engraving tool with a corresponding flank angle (α) is used for engraving.
55. A method according to claim 55, characterized in that a tapered rotating chisel is used for engraving.
56. A method according to any of claims 44 to 56, characterized in that a first engraving is engraved into the printing plate surface (2), and a second engraving is engraved into the printing plate surface (2) adjacent to the first engraving so as to leave between the first and second engravings a partition (4) tapering at the level of the printing plate surface (2) or slightly therebelow.
57. A method according to any of claims 44 to 58, characterized in that the mutual maximum distance (d) of the partitions (4) is smaller than 500 microns.
58. A method according to claim 59, characterized in that the mutual maximum distance (d) of the partitions (4) is 20 microns to 150 microns.
59. A method according to any of claims 44 to 60, characterized in that partitions (4) with different heights are provided within an engraving.
60. A method according to any of claims 44 to 60, characterized in that the engraved area engraved into the printing plate surface (2) has an engraving depth in the range of 5 microns to 150 microns.
61. A method according to claim 62, characterized in that the engraving depth is in the range of 10 microns to 60 microns.
62. A method according to any of claims 49 to 63, characterized in that the partitions (4) form a linear fine structure through their parallel arrangement.
63. A method according to any of claims 49 to 64, characterized in that a first fine structure is engraved in at least a first engraved area, and a second fine structure different from the first fine structure is engraved in at least a second engraved area.
64. A method according to claim 63, characterized in that the partitions (4) in the first engraved area are produced with a different orientation from the partitions (4) in the second engraved area.
65. A method according to claim 64, characterized in that the partitions (4) in the first engraved area are aligned at right angles to the partitions (4) in the second engraved area.
66. A method according to any of claims 63 to 65, characterized in that the first engraved area is engraved with a different engraving depth (t) from the second engraved area.
67. A method according to any of claims 63 to 66, characterized in that the partitions (4) in the first engraved area are disposed at a greater maximum mutual distance (d) than the partitions in the second engraved area.
68. A method according to any of claims 63 to 67, characterized in that the upper edges (5) of the partitions (4) in the second engraved area are produced at a greater distance (a) from the printing plate surface (2) than the upper edges (5) of the partitions in the first engraved area.

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