ES2606058T3 - Dehydrating screen for paper production with a watermark - Google Patents

Abstract

Dehydrator screen for the production of paper with a watermark, the dehydrator screen presenting a support screen with a sieve surface, on which paper accumulates, as well as a watermark insert of perforated plastic material arranged in an area Partial of the support screen, characterized in that - the watermark to be produced during the paper production comprises as a motive component at least one gray development line with a width of 1.0 mm or less, which presents along of its length or width a gray development with continuous progression and - the watermark insert of plastic material for the production of the gray development line (s) comprises at least one linear motif element with a width 1.0 mm or less, which has a continuous progression zone along its length or width, in which the distance from the surface of the screen increases with continuous progression from a first distance value to a second greater distance value.

Description

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DESCRIPTION

Dehydrating screen for paper production with a watermark

The invention relates to a dehydrating screen for the production of paper with a watermark, as well as to a process for the production of such a dehydrating screen.

During the production of paper in machines with round sieve or machines with elongated sieve, paper mass is continuously stored on a mobile dehydrating sieve and solidified to such an extent that it can be evacuated as a wet paper web, for later processing, from the dehydrating sieve. Especially security papers for banknotes, identification documents and the like are often provided with security of watermarks, which allow a verification of the authenticity of the security paper and serve at the same time as protection against unauthorized reproduction .

Watermarked paper can be equipped with both two-level watermarks with a strong light-dark effect, as well as multi-level watermarks with smooth transitions between light and dark and detailed representation of a motif. For the production of multi-level watermarks, for example, a metal dewatering screen, a desired three-dimensional relief, is stamped. The paper thickness of the finished paper is then in correspondence of the embossed pattern and allows to recognize smooth, gradual transitions between lighter and darker areas.

From WO 2008/071325 A1 it is also known for this purpose the use of a watermark insert molded by injection, which forms a multi-level relief in the form of the watermark to be produced.

Starting from this, the invention is based on the task of indicating a dehydrating screen for the production of paper with a watermark, which brings together an attractive visual image with high security against counterfeiting.

This task is solved by the features of the independent claims. Subject to the secondary claims, improvements of the invention. The invention comprises a dehydrating screen of the aforementioned type, in which, the watermark to be produced during the production of the paper, comprises as a component of the motive at least one gray development line with a width of 1.0 mm or less, which presents along its length or width, a gray development with continuous progression. The dehydrating screen has a support screen, with a sieve surface, on which paper accumulates, as well as a watermark insert of perforated plastic material arranged in a partial area of the support screen. The watermark insert of plastic material comprises for the production of the gray development line (s) at least one linear motive element with a width of 1.0 mm or less, which it presents along its length or width is an increase zone with continuous progression, in which the distance from the surface of the screen increases with continuous progression from a first distance value to a second greater distance value.

Within the framework of this description, the surface of the support screen, on which paper accumulates, as a sieve surface arranged above, the opposite sieve surface, as a sieve surface arranged below, so that the indications "by above the sieve surface ”or“ below the sieve surface ”have a clear meaning.

The distance values are considered in this case, from the screen surface upwards, that is, in the direction towards the accumulated paper, positive, in the opposite direction, negative. It is provided in a particularly advantageous manner, that the first distance value of the increase zone with continuous progression extends from the sieve surface downwards, that is, that it is negative, and that the second distance value extends from the surface Screen up, that is, be positive. The gray development line produced during the production of the paper then shows, when observed in the light, a gray development with continuous progression, ranging from gray values that are lighter than the gray value of the surrounding banknote paper the watermark, to gray values that are darker than the gray value of the banknote paper.

The increase can also be extended, however, from a larger negative value as far as its value is concerned to a lower one as far as its value is concerned, or from a lower positive value as far as its value refers to a larger one. as far as its value is concerned, so that the increase zone develops completely below or above the sieve surface. The gray development lines produced then show a gray development, whose gray values range from very dark to less dark and from very light to less light, referring to the surrounding banknote paper.

In any case, it is provided with particular advantage that the first and second distance values meet the correlation criteria

Aa>% amean

where Aa = | a2 - ai | the difference in distance values and representing amean =% (| ai | + | a2 |) the average distance in terms of value. In this case the modification of the distance due to the increase is at least half of the average absolute distance of the sieve surface, so that it is a development line of

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Gray rich in contrasts.

The linear pattern element advantageously has a width of less than 0.6 mm, preferably less than 0.5 mm, particularly preferably less than 0.4 mm. In addition, the length of the linear pattern element is advantageously more than 5 times, particularly more than 10 times as large as the width of the linear element. Particularly advantageously, all linear motif elements of the watermark insert comply with the indicated size indications.

A particularly well defined image results when each magnification zone that extends along the length of a motif element is more than 5 times, particularly more than 10 times as large as the motif element width, and / or each magnification zone that extends along the width of the motif element occupies the entire width of the motif element.

Linear motif elements can be straight, but also have a curved, particularly wavy configuration. In advantageous configurations, the plastic watermark insert contains a plurality of the mentioned linear motif elements, which are arranged in the form of a geometric pattern, a bar code, a stroke or a guilloche.

In a refinement of the invention, the watermark insert of plastic material comprises, in addition to the one or several linear motif elements, also a flat extension relief area for the production of a development watermark. The flat extension relief area has a dimension of 5 mm or more in each direction, particularly 10 mm or more. In this case, at least one of the aforementioned linear motif elements can extend at least partially along the contour of the flat extension relief area and, due to this, highlight the development water mark produced by it.

In an advantageous configuration, the watermark insert is an injection molded insert. The injection molded insert is conveniently formed from a hydrophobic plastic material, for example, from polyoxymethylene. For wear reduction during operation, there may be added wear reduction additives to the plastic material.

Although at this time the injection molding process is preferred for the production of the watermark insert, the watermark insert may also be produced by deep drawing procedure or hot stamping procedure. In all production processes, a separate watermark insert can be produced first and drilled, and then the separately produced watermark insert attached to the support screen, particularly welded or glued. Alternatively, it is also possible, for example, to firstly insert a plastic material insert in the support screen, and produce a watermarking insert, using a deep drawing method or hot stamping procedure, a watermark insert. In a subsequent procedure step, the watermark insert integrated in the support screen is then perforated, possibly together with the support screen. When a deep drawing process can be used, a plaque of previously perforated plastic material can also be used, so that the subsequent perforation step can be suppressed. Finally, the watermark insert with a corresponding tool mold can also be injected directly into a partially cut area of the sieve fabric, so that a particularly close connection with the sieve tissue results. The dehydrating screen may also have an overinjection of plastic material or a subsequent injection of plastic material, which joins the watermark insert with the support screen.

The watermark insert is preferably arranged in a cut-off area of the support screen and joined thereto only by a preferably serrated edge area. This can be done, for example, with the help of a laser cutting device, in the place of the screening path, in which the watermark insert is provided, a recess, which is somewhat smaller, for example, 1 / 10 mm smaller, than the desired shape of the watermark insert. The edge zone may be configured particularly in the form of a pattern, preferably in a dentate shape. In this partially trimmed area, the watermark insert may be placed or preferably injected, as described above.

The support screen advantageously comprises a screen fabric with at least respectively a system of warp threads, which extend in the longitudinal direction and weft threads, which extend transversely with respect to them, woven between them, comprising the fabric of Advantageously screening a metal fabric, particularly a bronze fabric, a mixed metal-plastic material fabric, particularly a mixed bronze-plastic material fabric, or a fabric of pure plastic material.

The watermark insert also preferably has multiple perforations, which ensure drainage during paper production. The dimensions of these dehydration perforations are chosen so small, that fibers do not adhere to them during paper production. Typical drilling diameters are between 100 pm and some 100 pm, preferably at approximately 500 pm. The perforations preferably narrow toward the design surface above the watermark insert.

The invention also comprises a process for the production of a dehydrating screen for the production of paper with a watermark, in which

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- during a paper production, a watermark to be produced is predetermined, which as a pattern component comprises at least one gray development line with a width of 1.0 mm or less, which is along its length or length. its width a development of gray with continuous progression,

- a support screen with a sieve surface for paper storage is made available,

- a watermark insert with at least one linear motif element with a width of 1.0 mm or less is injected by injection molding process in the support screen, the linear motif element being produced along its length. length or width with an increase zone with continuous progression, in which the distance with respect to the sieve surface increases with continuous progression from a first distance value to a second greater distance value, and

- The watermark insert is supplied by the laser radiation actuation of dehydration perforations.

Preferably, during the process, the support screen is trimmed in the area of the watermark to be produced, and the watermark insert is injected into the clipped area of the support screen. The watermark insert can alternatively also be produced as a separate watermark insert and drilled, and welded or glued with the support screen.

Other examples of realization, as well as advantages of the invention, are explained below by means of the figures, in whose representation a representation to scale and faithful to the proportions has been renounced, to increase the clarity.

They show:

Fig. 1 in schematic representation the image of a banknote with a watermark with several gray level lines in the light,

Fig. 2 a cross section through the banknote in the area of one of the first gray level lines along the line II-II of Fig. 1,

Fig. 3 a cross section through the banknote transversely with respect to the second gray level lines along the MI-MI line of Fig. 1,

Fig. 4 a schematic representation of a dehydrating screen according to the invention, which is used for the production of watermarks with gray development lines,

Fig. 5 a cut-out of a watermark insert molded by injection, which is used for the production of the second gray development lines of Fig. 1,

Fig. 6 a watermark insert with a linear motif element, which has several zones of increase with continuous progression,

Fig. 7

a watermark insert of a dehydrating screen according to the invention with other types of linear motif elements, and

Figs. 8, 9 two more complex watermark configurations, in which the gray development lines are combined with other known design elements of conventional watermark configurations.

The invention is now explained by the example of watermarks for banknotes. Figures 1 to 3 show for this in schematic representation, a banknote 10, in whose paper substrate 12 a watermark with first and second gray development lines 14, 16 with gray development with continuous progression has been introduced . Fig. 1 shows in this case the image of the banknote in the light, Fig. 2 a cross section through the banknote in the area of one of the first gray level lines along the line II -II of Fig. 1, and Fig. 3 a cross section through the banknote transversely with respect to the second gray level lines 16 along line III-III of Fig. 1.

When seen in the light, for example, against daylight or a luminous lamp, the banknote paper is not completely opaque in the unprinted areas, but rather translucent, and therefore appears with a certain value of gray 12 -M, which in Fig. 1 is indicated by a medium thickness scratch.

The first gray development lines 14 of the watermark, have a width of only 0.6 mm and show a gray development with continuous progression along its longitudinal direction, ranging from a gray value very light to a very dark gray value. Due to design reasons, the development of grays actually with continuous progression is illustrated in Fig. 1 by several discrete scratch levels, indicating a reduced or white scratch thickness a light gray value and a high or black density thickness. A value of dark gray. As shown in Fig. 1, the gray values of the gray development line 14 range from 14-H gray values, which are lighter than the 12-M gray value of the banknote paper, a 14-D gray values, which are darker than the 12-M gray value of banknote paper.

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The second gray development lines 16 have a width of 1.0 mm and show a gray development with continuous progression along its transverse direction, that is to say its width, ranging from a gray value very light to a very dark gray value. Also illustrated here due to design reasons, the development of grays actually with continuous progression, by means of several discrete scratch levels, the gray values of the gray development line going, of 16-H gray values, which are lighter than the 12-M gray value of the banknote paper, at 16-D gray values, which are darker than the 12-M gray value of the banknote paper.

For the indication of different paper thicknesses in the area of the gray development lines 14, 16, Figures 2 and 3 show cross sections along the line II-II or NI-NI of Fig. 1. The Theoretical thickness of banknote paper 12 outside the gray development lines 14, 16 is indicated in this case with So.

As shown in Fig. 2, the first gray development lines 14 consist of a single area of increase, in which the paper thickness increases along the longitudinal direction of the line, from a low value Sh, which produces a light 14-H gray value during the light observation, with continuous progression, up to a higher Sd value, which produces a darker 14-D gray value during the light observation. In the transverse direction of the gray development lines 14, the paper thickness is constant. Since in the example of embodiment shown, Sh <S0 <Sd is additionally valid, the light 14-H gray value is lighter and the dark 14-D gray value is darker than the average 12-M gray value of banknote paper.

The second gray development lines 16 also consist respectively of a single area of increase, in which the thickness of paper increases however along the transverse direction of the lines, from a low value Sh <So with continuous progression to a higher value Sd> So. In the longitudinal direction of the gray development lines 16, the paper thickness is constant, so that the gray development generally described above results in light.

In the case of round sieve watermarks or conventional electrotype watermarks, this type of narrow lines cannot be produced with a gray development with continuous progression. To produce watermarks with gray development lines of the type described, a dehydrator screen 40 schematically represented in cross-section in Fig. 4 is used according to the invention.

The dehydrating screen 40 comprises a support screen 42 with a screen fabric 44, which is cut in a partial area 50. The height level of the surface directed towards the paper, of the support screen, is indicated in Fig. 4 by reference 52. During paper production, paper is accumulated on screen fabric 44, whose theoretical thickness is indicated after drying with So (Figures 2 and 3).

The screening fabric 44 has at least respectively a system of warp threads 46 with extension in the longitudinal direction and weft threads 48 of transverse extension with respect thereto, woven to each other In the context of the present invention, the screening fabric may comprising, for example, a metal fabric, particularly a bronze fabric, a mixed metal-plastic material fabric, particularly a mixed bronze-plastic material fabric, or also a pure plastic material fabric. The support screen 42 can comprise both a single layer screening fabric, as well as one of several layers, being shown in the figures due to reasons of a simpler representation, only single layer screening fabrics.

In the partial zone 50 cut out of the screen fabric 44, a watermark insert of plastic material 60 is disposed, which is connected at its edge with the screen fabric 44. The union can be produced basically in several ways, for example , by over-injection or subsequent injection of plastic material, with the help of a plurality of fixing buttons arranged along the edge, or also by welding or gluing.

In the exemplary embodiment, there is another variant, in which the insert of the watermark of plastic material 60 is an injection molded element, which is injected with a corresponding tool mold directly into the cut-out partial zone 50 of the screen fabric 44 and which in this case results in a particularly deep union with the screen fabric.

The watermark insert 60 molded by injection presents for the production of a gray development line 14, a linear motif element 62, with a width of 0.6 mm, which consists of a single area of increase, in the which increases the distance with respect to the surface of the screen 52 along its longitudinal direction L with continuous progression, from a first distance value a1 at the right end 64-1 of the motif element 62 to a second distance value a2 greater at the left end 64-2 of the motif element 62. As explained above, the distances from the screen surface 52 upwards, that is, in the direction of the paper being accumulated, the distances from sieve surface 52 down, negative.

In the exemplary embodiment of Fig. 4, the distance value a2 is positive, the left end 64-2 is therefore above the screen surface 52, and the distance value a1 is negative, so that the right end 64-1 is below the surface of the screen 52. During paper production, the right end 64-1 of the pattern element 62 produces an area with increased paper thickness Sd> So, the end left 64-2 produces a zone with reduced paper thickness Sh <So, and the zone of increase with progression

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60

continuous between the two ends 64-1, 64-2 produces a paper thickness that increases with continuous progression from Sh to Sd, so that in total a gray development line 14 results with the image described in Fig. 1.

The watermark insert 60 is also provided with multiple perforations 58 only indicated in the figure, to ensure drainage during paper production also in the area of the watermark insert. The diameter of the perforations 58 is chosen in this case in such a way that fibers do not adhere to them during paper production. Typical drilling diameters are between 100 pm and some 100 pm, for example at 500 pm.

Fig. 5 shows a cut of a watermark insert 70 molded by injection, which is used for the production of the gray development lines 16 of Fig. 1. Due to a simpler representation, the support screen and the perforations have been omitted in this and in the successive figures. The watermark insert 70 may also be configured in one piece with the watermark insert 70 of Fig. 4. The watermark insert 70 comprises three linear pattern elements 72 with a width of 1.0 mm , whose longitudinal direction is perpendicular with respect to the plane of the paper in the representation of Fig. 5. Each motif element 72 consists of a single zone of increase, in which the distance from the screen surface 52 increases along its transverse direction Q with continuous progression, from a first distance value a1 in a longitudinal edge of the motif element to a second distance value a2 greater, in the opposite longitudinal edge of the motif element. During paper production, the longitudinal edge with the negative distance value a1 produces an area with increased paper thickness Sd> So, the longitudinal edge with the positive distance value a2 produces an area with reduced paper thickness Sh <So, and the zone of increase with continuous progression between the two longitudinal edges produces a paper thickness that increases with continuous progression from Sh to Sd along the width, so that in total they are gray development lines 16 with the described image in Fig. 1.

Linear motif elements may also have several zones of continuous progression and thereby produce gray development lines with a more complex gray development. In the exemplary embodiment of Fig. 6, the watermark insert 80 comprises approximately a linear motif element 82 with a width of 0.4 mm, which has four magnification zones with continuous progression 84-1 to 84- 4 along its longitudinal direction L. As shown in Fig. 6, the distance in zones 84-1 and 84-4 increases respectively from a negative value outward to the level of the screen surface 52, that is, at a distance value a = 0, while in zones 84-2 and 84-3 it increases from a negative value to the same positive value in the middle of the line. The pattern element 82 generally produces, during the production of paper, a gray development line with a succession of neutral / dark / light / dark / neutral clarity, calling the clarity of the surrounding banknote paper "neutral". The watermark insert 80 of Fig. 6 also illustrates that the increase should not develop linearly in the magnification zones.

Apart from that, the increase does not necessarily have to develop from a negative distance value to a positive one, but it can also be developed, for example, from a negative value as far as its value is concerned, larger, to a smaller one in as far as its value is concerned, as shown in the linear pattern element 86 on the left side of Fig. 7. The pattern element 86 produces a gray development line during paper production, whose gray values They range from a very dark image impression to a less dark one. Since the entire motif element 86 is below the screen surface 52, the entire gray development line produced appears darker than the surrounding banknote paper. Likewise, the increase from a smaller positive value as far as its value is concerned, can develop towards a larger one as far as its value is concerned, as shown in the linear motif element 88 on the right side of Fig. 7. The motif element 88 produces, during paper production, a gray development line, whose gray values range from a less clear image impression to a very clear one. The gray development line as a whole seems lighter than the surrounding banknote paper, since all of the motif element 88 is above the screen surface 52. Naturally, the increase can also begin or end. at the height of the sieve surface 52 with a distance value a = 0, as already illustrated in Fig. 6.

Regardless of the sign of the two distance values, the first and second distance values of an increase zone advantageously meet the correlation Aa> A * amean, with Aa = | a2 - a11 being the difference of the distance values and representing amean = A (| ai | + | a2 |) the average distance in terms of value. In this case, the modification of the distance due to the increase is at least half of the average absolute distance of the screen surface 52, so that in any case it is a gray development line with an image rich in contrasts. If a gray development line comprises several zones of increase with continuous progression, then the aforementioned correlation is advantageously fulfilled in each zone of increase.

The watermarks to be produced can naturally have more than one gray development line and in addition to the gray development lines, also comprise other known design elements of conventional watermark configurations. The gray development lines also do not have to be developed in a straight line, but they can be configured in a curved, particularly undulating manner, and form, for example, a stroke or a guilloche pattern, or also completely or partially follow the outline of a mark of conventional development water. By way of example only two more complex watermark configurations with gray development lines are depicted in Figures 8 and 9. Due to the above explanations, it is clear to

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the expert how to configure a corresponding watermark insert for the production of these watermarks.

Fig. 8 shows a top view of a banknote paper 20 with a watermark 22, comprising four gray development lines 14 according to Fig. 1 with a width of only 0.6 mm, arranged in a square. Inside the square the value figure "10" is arranged in the form of a highlighted watermark 24 of very clear appearance to the light. In the corresponding watermark insert, in addition to the linear motif elements already described, there are also two motif elements that clearly exceed the screen surface 52, in the form of the figures "1" and "0", which do not comprise any zone of increase and are therefore considered by the present description as conventional design elements.

In the case of the example of embodiment of Fig. 9, the watermark 30 comprises a gray development line 14 and a gray development line 16 according to Fig. 1, which are combined with a development watermark 32 conventional. For this, the corresponding watermark insert, in addition to the linear motif elements 62 or 72 already described, also a flat extension relief area, for the production of the development watermark 32. At least one line Gray development can also be developed completely or partially along the contour of the development watermark 32 and accentuate it because of this more strongly.

Reference List

10

12

12-M

14

14-H, 14-D 16

16-H, 16-D 20 22 24 30 32 40 42 44 46 48 50 52 58 60 62

64-1, 64-2

70

72

80

82

84-1 to 84-4

86

88

L

Q

a1

a2

Banknote Paper Substrate Value of Gray

First gray level lines

Light gray or dark values

Second gray level lines

Light gray or dark values

Banknote paper

Watermark

Featured Watermark

Watermark

Watermark development

Dehydrating Screen

Support Screen

Sieve fabric

Warp threads

Weft threads

Trimmed partial zone

Height level screen surface

Perforations

Watermark insert

Linear motif element

Right or left end

Watermark insert

Linear motif element

Watermark insert

Linear motif element

Increase zones with continuous progression

Linear motif element

Linear motif element

Longitudinal direction

Cross direction

First distance value

Second distance value

Claims (17)

5 10 fifteen twenty 25 30 35 40 Four. Five fifty 1. Dehydrating screen for the production of paper with a watermark, the dehydrating screen presenting a support screen with a sieve surface, on which paper accumulates, as well as a watermark insert of perforated plastic material arranged in a partial area of the support screen, characterized in that - the watermark to be produced during paper production comprises as a pattern component at least one gray development line with a width of 1.0 mm or less, which along its length or width has a gray development with continuous progression and - the watermark insert of plastic material for the production of the gray development line (s) comprises at least one linear motive element with a width of 1.0 mm or less, which it presents along of its length or width an area of continuous progression increase, in which the distance from the surface of the screen increases with continuous progression from a first distance value to a second greater distance value. 2. Screen dehydrator according to claim 1, characterized in that the first distance value of the increase zone with continuous progression extends from the screen surface downwards and the second distance value from the screen surface upwards. 3. Screen dehydrator according to claim 1 or 2, characterized in that the first and second distance value comply with the relationship Aa> A * amean, with Aa = | a2 - a11 being the difference of the distance values and representing ame-an = A (| ai | + | a2 |) the average distance in terms of value. 4. Dehydrator screen according to at least one of claims 1 to 3, characterized in that the linear pattern element has a width of less than 0.6 mm, preferably less than 0.5 mm, particularly preferably less than 0 , 4 mm. 5. Screen dehydrator according to at least one of claims 1 to 4, characterized in that the linear pattern element has a length and width, the length being more than 5 times, particularly more than 10 times, the size of the width. 6. Screen dehydrator according to at least one of claims 1 to 5, characterized in that each increase zone that extends along the length of a pattern element is more than 5 times, particularly more than 10 times, the size of the width of the motif element, and / or why each magnification zone that extends along the width of a motif element occupies the entire width of the motif element. 7. Screen dehydrator according to at least one of claims 1 to 6, characterized in that the linear motif elements mentioned have a straight or curved, particularly wavy, configuration. 8. Dehydrating screen according to at least one of claims 1 to 7, characterized in that the watermark insert of plastic material comprises a plurality of the mentioned linear motif elements, which are arranged in the form of a geometric pattern, of a barcode, a stroke or guilloche. 9. Dehydrator screen according to at least one of claims 1 to 8, characterized in that the watermark insert of plastic material comprises, in addition to one or more of the mentioned linear motif elements, a flat extension relief area for the production of a development watermark. 10. Screen dehydrator according to claim 9, characterized in that one of the mentioned linear motif elements extends at least partially along the contour of the flat extension relief area. 11. Screen dehydrator according to at least one of claims 1 to 10, characterized in that the watermark insert is an injection molded insert. 12. Dehydrator screen according to at least one of claims 1 to 11, characterized in that the dehydrator screen has an overinjection of plastic material or a subsequent injection of plastic material, which joins the watermark insert with the support screen. 13. Screen dehydrator according to at least one of claims 1 to 12, characterized in that the watermark insert is disposed in a cut-off area of the support screen and joined thereto only by a preferably serrated edge area. 14. Screen dehydrator according to at least one of claims 1 to 13, characterized in that the support screen has a screen fabric with at least correspondingly a system of warp threads that extend in the longitudinal direction and weft threads that extend transversely with respect thereto, woven together, advantageously comprising the screening fabric or a metal fabric, particularly a bronze fabric, a mixed metal-plastic material fabric, particularly a mixed bronze-plastic material fabric or a fabric of pure plastic material. 15. Screen dehydrator according to at least one of claims 1 to 14, characterized in that the insert of Watermark has multiple perforations, the dimensions of which are so small that fibers do not adhere to them during paper production. 16. Procedure for the production of a dehydrating screen for the production of paper with a watermark, in which 5 10 fifteen 17. Method according to claim 16, characterized in that the support screen is trimmed in the area of the watermark to be produced and the watermark insert is injected into the clipped area of the support screen. - a watermark to be produced during paper production is predetermined, which as a pattern component comprises at least one gray development line with a width of 1.0 mm or less, which is along its length or length. its width a development of gray with continuous progression, - a support screen with a sieve surface for the accumulation of paper is made available, - a watermark insert with at least one linear motif element with a width of 1.0 mm or less is injected by an injection molding process in the support screen, the linear motif element being produced along its length or width with an increase zone with continuous progression, in which the distance with respect to the sieve surface increases with continuous progression from a first distance value to a second greater distance value and - The watermark insert is supplied by the laser radiation actuation of dehydration perforations.