WO2015085438A1

WO2015085438A1 - Security document with stress compensated foil element

Info

Publication number: WO2015085438A1
Application number: PCT/CH2013/000216
Authority: WO
Inventors: Martin Eichenberger; Dieter Sauter
Original assignee: Orell Füssli Sicherheitsdruck Ag
Priority date: 2013-12-09
Filing date: 2013-12-09
Publication date: 2015-06-18

Abstract

The security document comprises a foil element (5) applied to a first side (6) of a substrate (1) as well as a counter layer (8) applied in the same lo-cation at a second side (7) of the substrate (1). The foil element (5) is over its entire extension bound to the substrate (1) and is comparatively thick. Counter layer (8) serves to reduce a tendency of the foil element (5) to cause a buckling of the substrate (1) and has blurred edges (10c, 10d) in order to decrease mechanical stress of the substrate (1) and visibility of the counter layer (8).

Description

Security document with stress compensated foil element

Technical Field

The invention relates to a security document comprising a flexible substrate and a foil element arranged on the substrate.

Background Art

It is generally known to apply a foil element to the substrate of a security document. The foil element advantageously carries a security feature, such as a dif- fractive pattern, a holographic image, a metallization, etc .

While the foil element is typically arranged over a continuous area of the substrate, it has also been known to apply the foil element over an opening in the substrate in order to form a mechanically closed, but transparent or translucent window in the document. For example, WO 2011/015662 describes a security document having a carrier with an opening. A window is formed at the location of this opening by covering the opening with a foil element. A counter layer is applied to a side of the security document that faces away from the side of the foil element. The counter layer does not extend into the opening.

Disclosure of the Invention

The problem to be solved by the present invention is to provide a durable security document of this type.

This problem is solved by the security document of claim 1. Accordingly, the security document com^¬ prises a substrate having opposed first and second sides. A foil element is arranged on the first surface side of the document and covers a "foil element area", i.e. the "foil element area" is defined as the area of the document over which the foil element extends . A counter layer is arranged opposite to the foil element on the second surface side of the substrate. This counter layer substantially extends over at least said entire foil element area.

In other words, the counter layer's lateral extension is such that it substantially covers at least those parts of the document that are also covered by the foil element.

Hence, the counter layer covers substantially all of the "back side" of the foil element, thereby pro^¬ tecting it completely.

Advantageously, in this context the term "substantially extends" and "substantially covers" are to be understood such that the counter layer covers at least 95%, in particular at least 99%, in particular 100% of the foil element area (and, optionally, regions extending beyond the foil element area) .

Advantageously, the counter layer is a poly- meric counter layer, i.e. the counter layer is polymerized at least partially. Such a polymeric counter layer has low water permeability and high mechanical stability and is therefore well able to counteract the foil element's tendency to buckle the substrate.

In another advantageous embodiment, the foil element and the counter layer each extend along a first direction between first and second opposite outer side edges of the substrate, while they do not extend over all the substrate in the direction perpendicular to said first direction. In other words, the foil element and counter layer form stripes extending over the width or breadth of the substrate. It has been found that the bending induced by the foil element can, in this case, be efficiently compensated by the counter layer.

At most or all of the locations where the edge of the foil element does not coincide with an edge of said substrate, the counter layer advantageously ex^¬ tends by a non-zero distance lateral distance beyond the foil element. In other words, the counter layer extends further than the foil element and therefore securely pro^¬ tects the foil element even in the presence of a small misalignment between foil element and counter layer.

Advantageously, at least one edge of the counter layer is blurred, i.e. the density of the counter layer decreases gradually along the edge. When using a substantially transparent or translucent counter layer or a counter layer having substantially the same colour as the substrate, a blurred edge renders the counter layer less visible. In addition, a gradual transition of the density of the counter layer provides for a mechanically smoother transition between coated and non-coated re- gions, which decreases mechanical stress.

In an advantageous embodiment, and as men^¬ tioned, the counter layer is transparent or translucent or has substantially the same colour as said substrate, thereby making it substantially invisible.

The document can further comprise at least one print layer of printed ink. This print layer can be located above the counter layer, and it can in particular be applied to the counter layer. In this case, the counter layer can e.g. act as an underground or primer for the print layer and the print layer can at least partially hide the counter layer.

Alternatively, the print layer can be located below the counter layer, and it can in particular be covered by the counter layer. In this case, the counter layer can protect and/or hide the print layer at least par^¬ tially.

The print layer is, in a particularly advantageous embodiment, an offset print layer.

The document can be manufactured by the steps of applying said foil element to said first side and said counter layer to said second side, wherein said steps can take place in any order.

Advantageously, the counter layer is applied by applying a UV hardening composition to said second side and by subsequent hardening the applied composition by means of UV radiation. In particular, the composition can be at least partially polymerized by being exposed to UV radiation.

Other advantageous embodiments are listed in the dependent claims as well as in the description below.

Brief Description of the Drawings

The invention will be better understood and objects other than those set forth above will become ap^¬ parent from the following detailed description thereof. Such description makes reference to the annexed drawings, wherein :

Fig. 1 shows a view of a first side of a security document,

Fig. 2 shows a view of a second side of the security document, with only the counter layer shown (in black) , Fig. 3 is a sectional view along line III-III of Fig. 1,

Fig. 4 shows the decay of the average density of the counter layer at a blurred and non-blurred edge thereof,

Fig. 5 shows a second embodiment with the counter layer applied over the offset print layer,

Fig. 6 an alternative embodiment of the design of the counter layer,

Fig. 7 shows an embodiment of the counter layer with machine-readable surface structures,

Fig. 8 shows an embodiment where the foil element and the counter layer are arranged in recesses of the substrate,

Fig. 9 shows an embodiment where a window is arranged in the substrate at the location of the foil el^¬ ement ,

Fig. 10 shows an embodiment where a half- window is arranged in the substrate at the location of the foil element.

Modes for Carrying Out the Invention

Definitions :

The term "document" relates to a sheet-like flexible object carrying printed information on at least one of its surfaces.

The terms "lateral" and "laterally" refer to all directions extending parallel to a surface of the security document.

Terms of the type "above", "below", "top" and "bottom" are understood in respect to a center plane of the substrate, which center plane extends parallel to the surfaces of the document. Any object A closer to the cen- ter plane than an object B is below object B and object B is on top of object A.

A counter layer is "transparent" or "translucent" if it transmits at least 80% of all light in the visible spectrum.

A "flexible" substrate or document is a substrate or document that can reversibly be bent to a curvature of 10 mm or less.

A "foil element" is a piece of foil applied to the document. The foil can e.g. be of plastics or met^¬ al or a combination of these materials. The foil element covers only part of the document, in particular no more than 20%, in particular no more than 10%, of the document. It may e.g. take the form of a foil patch laterally surrounded on all sides by the substrate, or it may be a stripe extending over the whole width or length of the document .

Embodiments :

A first embodiment of the invention is illus^¬ trated in Figs. 1 - 3. These figures show a security doc^¬ ument in the form of a banknote.

The shown security document comprises a flexible substrate 1 of paper (conventional paper or cotton- based paper) and/or plastics, onto which graphical elements, for example in the shape of security designs 2, illustrations 3 and indications of value 4, are printed in known manner. In addition the document comprises a foil element 5 arranged on a first side 6 thereof, as shown in Fig. 1.

Foil element 5 can be any security patch as typically used in security documents. It may e.g. comprise at least one metal or plastic layer and can e.g. carry diffractive structures, such as a surface grating and/or a volume hologram. Foil element 5 covers an area of the security document that is subsequently called the "foil element area". Advantageously, and as can be seen from Fig. 3, every part of foil element 5 is directly or indirectly laminated to substrate 1, i.e. there are no holes or openings in substrate 1 below foil element 5.

Still, foil element 5 is advantageously a comparati ely thick patch, with a thickness of at least 20 μπι. Such thick patches, which are typically only used in window forming applications to extend over openings or holes in substrate 1, have various advantages also in the present application. In particular, they can hold more refined security features, such as multi-layer structures and/or efficient volume holograms. However, they tend to cause a bending or buckling of the substrate. This tendency is, in the present document, counteracted by a counter layer 8 on the opposite, second side 7 of substrate 1.

Alternatively, foil element 5 can also be thinner than 20 μπι, e.g. in the range of 5 - 20 μπι, in particular if foil element 5 is applied by hot stamping instead of lamination. Such thin foil elements 5 may also lead to a buckling of the substrate mainly because they are more or less impermeable to water and therefore tend to generate a non-uniform humidity distribution over the thickness of the substrate.

Hence, foil element 5 advantageously a thickness of at least 5 μιτι, in particular between 5 - 20 μπι or of at least 20

Fig. 2 shows this second side 7 of substrate 1 and illustrates counter layer 8. Counter layer 8 is ar- ranged opposite foil element 5. Advantageously, counter layer 8 has substantially the same shape as foil element 5 and is in alignment therewith. Counter layer 8 covers at least the foil element area, i.e. wherever there is a section of foil element 5 on first side 6, there is a section of counter layer on second side 7.

Counter layer 8 is advantageously a polymeric counter layer, i.e. it is at least partially polymerized. Such counter layers are less permeable to water and mechanically stringer, thereby counteracting a bending of the substrate caused by patch layer 5 more efficiently.

Advantageously, counter layer 8 has a specif- ic weight (weight per surface area) of at least 10 g/m2 in order to counteract a strong bending tendency of foil element 5. A typical thickness of counter layer 8 lies in the range of 5 - 20 μτη, in particular 10 - 14 μτ .

As can be seen from Figs. 1 and 2, foil ele- ment 5 as well as counter layer 8 extend all the way between first and second opposite side edges 9a, 9b of substrate 1, i.e. they extend all the way along a first direction XI across the substrate. However, along a second direction X2 perpendicular to XI, they do not extend over all of substrate 1.

The extension of foil element 5 as well as counter layer 8 along first direction XI is advantageously larger than along second direction X2, i.e. patch 5 and counter layer 8 form stripes extending across sub- strate 1. For example, a typical width wl along direction X2 (see Fig. 3) of foil element 5 as well as the corre^¬ sponding width w2 of counter layer 8, is between 5 and 50 mm, in particular between 10 and 20 mm.

In the shown embodiment, counter layer 8 has four edges 10a, 10b, 10c, and lOd. Two of these, namely edges 10a and 10b, coincide with an edge of substrate 1 and with an edge of foil element 5. The two other edges 10c, lOd, however, do not coincide with an edge of sub^¬ strate 1, but rather lie somewhere within the contours of substrate 1. At the location of these two edges 10c, lOd, counter layer 8 laterally extends by a non-zero distance D beyond the corresponding edges of foil element 5 (see Fig. 3) . This overlap ensures that counter layer 8 securely covers the whole foil element area even if foil element 5 and counter layer 8 are slightly misaligned.

Advantageously, in order to compensate for typical misalignment errors, distance D is at least 0.5 mm, in par- 2013/000216

9 ticular at least 1.0 mm. If foil element 5 and counter layer 8 are perfectly aligned, D can e.g. be designed to be 2 mm.

As shown in Fig. 2, the edges 10c, lOd of counter layer 8 are blurred, i.e. the density gradually decreases across these edges. In this context, the term "density" is understood as the locally averaged specific weight (weight per area) of counter layer 8. This blurring of the edges makes counter layer 8 less visible and reduces the formation of local stress regions in the area of the edges. The blurring can be causes by thinning counter layer 8 at its edges or, as shown in Fig. 2, by an increasingly less dense rasterization or patterning. In the latter case, the density (which gradually decreas- es at the edge) has to be defined as a local average of the weight of counter layer 8.

For example, the local density p of counter layer 8 can be defined as the weight of counter layer 8 averaged over a circular area of diameter d, where diame- ter d should be much smaller than a width w2 of counter layer 8 but much larger than a rastering size of counter layer 8. Typically, diameter d can be selected in a range between 0.5 and 5 mm. With this definition, an edge of counter layer 8 is well blurred if the local density p gradually decreases across the edge of counter layer 8 over a width E > 2-d from its maximum value (the value over the bulk of counter layer 8) to zero for at least one diameter d, in particular for several diameters d over a range of at least 1 mm. (Note that for a non- blurred edge the width E equals d for all diameters d.) This is qualitatively illustrated in Fig. 4, which shows the density p as a function of the position along second direction X2. As it can be seen, the density p decreases over a width E from the maximum value to zero.

In the case of a counter layer 8 with blurred edges, the non-zero distance D mentioned above is defined as the distance between the edge of foil element 5 and the end of the "bulk" region of counter layer 8, as indicated in Fig. 3.

Even though shown in black in Fig. 2, counter layer 8 is advantageously chosen to be invisible. For this purpose, it can be transparent or translucent or it can have the same colour as substrate 1.

The security document typically carries printed matter also on its second side, even though no such matter is shown in Fig. 2. The printed matter can e.g. comprise offset print, screen print and/or intaglio print, carried out with standard inks and/or with security inks, such as optically variable inks.

Fig. 3 shows one such print layer 12. In this embodiment, print layer 12 is located above counter layer 8. Advantageously, it is directly or indirectly applied onto the counter layer, i.e. it overlaps the counter lay^¬ er, thereby rendering counter layer 8 less visible. In order to obtain a good camouflage of counter layer 8, print layer 12 can cover at least 50%, in particular at least 90% of counter layer 8.

Print layer 12 is advantageously an offset print layer, i.e. it is printed with offset inks in offset printing technology as known to the skilled person. Such offset printing is well suited for covering counter layer 8 and hiding it without imposing too much design restrictions on the security document.

Alternatively to the embodiment of Fig. 3, print layer 12 can also be located below counter layer 8. i.e. between counter layer 8 and substrate 1. In particu- lar, it can be covered at least partially by counter layer 8, as shown in the sectional view of the embodiment of Fig. 5.

In both embodiments of Fig. 3 and Fig. 5, the document advantageously comprises a varnish layer 14 in addition to counter layer 8. Varnish layer 14 covers at least part of print layer 12 and counter layer 8 and it extends over a larger area than counter layer 8, typical- ly over the entire security document. Varnish layer 14 protects counter layer 8 and print layer 12. A typical thickness of varnish layer 14 lies in the range of 1 - 3 μιτι, in particular 1.8 - 2.0 μκι.

Fig. 6 shows a second embodiment of the design of the counter layer. This embodiment shows two differences as compared to the one of Fig. 2.

For one, fine gaps are formed in counter layer 8, as shown by the crossed white lines. These gaps form a "negative pattern" and are advantageously thin, in particular with a width of 1 mm or less. Such gaps can increase the flexibility of the document in the foil element area. However, in order to avoid an excessive degradation of the protective function of counter layer 8, counter layer 8 should still cover at least 95%, in par^¬ ticular at least 99%, of the foil element area.

Further, the ^xxblurring" of the edges 10c and lOd of counter layer 8 is not implemented by an increasingly less dense rasterization, as in the embodiment of Fig. 2, but rather by patterning, i.e. by structuring the edge of counter layer 8 in order to gradually decrease the local density p of counter layer 8 as described above .

Fig. 7 shows yet a further embodiment of counter layer 8 including machine-readable surface structures 19 formed e.g. by a plurality of bumps and/or depressions. These structures can be observed by a suitable detection device, e.g. using specular reflection. Surface structures of this type are e.g. disclosed in US

2008/0149820 and can be used for authentication purposes. The lateral size L of the surface structures 19 is between 5 and 1000 pm, in particular between 10 and 500 μπι, such that they can be detected easily by means of a suitable detection apparatus. Alternatively to using surface structures of the type described in US 2008/0149820, other predetermined surface structures can be used, such as larger or smaller structures. The surface structures 19 can form a unique identifier for the given document. For example, the pattern formed by the surface structures can be a function of a serial number of the document. This allows improved tracking and/or authentication of the document. In yet another embodiment, another coding can be applied to the counter layer, in particular by means of an optically variable ink.

Method of manufacture:

The security document can, in one embodiment, be manufactured by the following steps:

(1) Providing substrate 1, typically in the form of a paper sheet encompassing several individual substrates side by side.

(2) Applying counter layer 8. Advantageously, screen printing is used for this purpose in order to ap^¬ ply a sufficient amount of counter layer. In a preferred embodiment, counter layer 8 is applied by applying a UV hardening composition to second side 7 and hardening this composition by UV radiation. A suitable composition is e.g. a UV polymerizable resin, such as type 9Z0D007 screen printing primer, semi-matte dual cure by Sicpa, which combines therrno drying and UV polymerization. When using screen printing, several different screens can be used for generating rasterized "blurred" edges 10c, lOd as shown in Fig. 2. A single, structured screen can be used for forming structured "blurred" edges 10c, lOd as shown in Fig. 6.

(3) Applying offset print to both sides of substrate 1. In this case, offset print 12 is applied on top of counter layer 8, as shown in the embodiment of Fig. 3.

(4) Applying foil element 5 to first side 6 of substrate 1, e.g. using a transfer or lamination techniques . (5) Applying any further printed elements, such as intaglio or screen print elements as well as any further security features.

(6) Applying varnish layer 14 to both sides of substrate 1. This varnish layer is advantageously ap^¬ plied using flexographic printing with a typical amount of 2 g/m^, i.e. varnish layer 14 is much thinner than counter layer 8. Varnish layer 14 may or may not cover security patch 5.

In order to manufacture a document according to Fig. 5, where counter layer 8 lies on top of offset print 12, steps (2) and (3) above can e.g. be reversed.

In both embodiments, foil element 5 is advantageously applied to substrate 1 after counter layer 8.

The above steps show one advantageous embodiment of the manufacturing process, but they can be varied depending on the design and features of the security document .

Surface structures 19, as shown in Fig. 7, can e.g. be formed by imprinting or embossing, but a particularly advantageous method for forming the surface structures 19 is ink jet printing, in particular if the surface structures 19 should be unique for each document. In this case, the ink-jet printing process can be used for applying the whole counter layer 8. Alternatively, counter layer 8 can be applied first, e.g. by means of screen printing, whereupon inkjet printing is used to form the surface structures 19 on top of counter layer 8. Further embodiments:

Fig. 8 shows a further embodiment of the in^¬ vention where foil element 5 and/or counter layer 8 are/is embedded at least partially in recesses 20, 21 in substrate 1. By embedding either one or both of these el- ements in substrate 1, the thickness of the document at the location of the foil element 5 can be reduced. Suitable recesses 20, 21 can be formed in substrate 1 using blind embossing (i.e. blind imprinting) or watermarking techniques.

The depth of the recesses 20, 21 is advantageously equal to the thickness of foil element 5 or counter layer 8, respectively, within an accuracy of +/- 20% or better.

Fig. 9 shows yet another embodiment where a window 22 is arranged in substrate 1 at the location of foil element 5. Window 22 is formed by an opening 23 extending all through substrate 1. Foil element 5 spans this opening. Counter layer 8 is again applied from the second side 7 to substrate 1 and also spans opening 23, thereby sealing also the edges of opening 23.

Fig. 10 shows an embodiment where a "half window" 24 is formed at the location of foil element 5. A half window is a window that does not extend all the way through the substrate. This type of windows can e.g. be manufactured in a multilayer-substrate.

In the embodiment of Fig. 10, substrate 1 is a multilayer-substrate comprising first and second paper layers 25a, 25b with a polymer layer 26 arranged between them. This type of substrate is e.g. manufactured under the name DuraSafe by Landqart, Switzerland.

An opening 27 is formed through one of the paper layers 25a, 25b. In the embodiment of Fig. 10, this opening 26 is arranged in layer 25a that faces first side 6. Foil element 5 spans opening 27 and is in contact with polymer layer 26. This allows e.g. to view the half win^¬ dow through foil element 5.

In more general terms, substrate 1 can be a multi-layer substrate having first and second outer substrate layers, such as the paper layers 25a, 25b, and one or more central substrate layers 26 arranged between said outer substrate layers. An opening 27 is formed through at least one of the outer substrate layers 25a, 25b.

While this opening extends through the respective outer substrate layer, it does not extend through the central substrate layer 26 (or, if there are several central substrate layers, it does not extend through all of them). The foil element 5 and the counter layer 8 span this opening 23.

In the embodiment of Fig. 10, opening 23 extends through outer substrate layer 25a at first side 6. Alternatively, opening 23 can extend through outer substrate layer 25b at second side 7. In yet a further alternative, openings can be formed through both outer layers 25a and 25b.

Notes :

The embodiments described above can be varied in numerous ways.

For example, counter layer 8 can e.g. be embossed or imprinted in order to form security elements therein, such as diffractive gratings.

In the above description of the manufacturing process, counter layer 8 is a coating, i.e. a layer that is hardened in place on the substrate, and it is applied by means of a printing process, in particular screen printing. Alternatively, counter layer 8 can be a foil member applied to the substrate in solid form, e.g. using lamination or hot stamping.

Further, the foil element area can be perfo^¬ rated using laser beams, such as disclosed in WO

97/18092. Such a perforation advantageously extends through foil element 5 as well as counter layer 8.

Also, even though counter layer 8 has been described as advantageously transparent, translucent or of the same colour as substrate 1, it can also be coloured and be used as a design element. In addition, it can be IR absorbing and/or fluorescent such that its presence can be verified using UV or IR radiation. In this context, an IR absorbing counter layer is a counter layer whose optical reflectivity is at no more than half the reflectivity of substrate 1 for at least one optical wavelength between 0.8 and 5 μπι.

While there are shown and described presently preferred embodiments of the invention, it is to be dis^¬ tinctly understood that the invention is not limited thereto but may be otherwise variously embodied and prac^¬ ticed within the scope of the following claims.

Claims

1. A security document comprising a flexible substrate (1) having opposed first and second sides (6, 7),

a foil element (5) arranged on said first side (6), wherein said foil element (5) covers a foil element area of said document,

a counter layer (8) arranged opposite to said foil element (5) on said second side (7),

wherein said counter layer (8) substantially extends over at least said entire foil element area.

2. The security document of claim 1 wherein said counter layer (8) is a polymeric counter layer (8).

3. The security document of any of the preceding claims wherein said foil element (5) and said counter layer (8) each extend along a first direction (XI) between first and second opposite side edges (9a, 9b) of said substrate (1), but do not extend over all said substrate (1) in a second direction (X2) perpendicular to said first direction (XI) .

4. The security document of claim 3, wherein an extension of each of said foil element (5) and said counter layer (8) along said first direction (XI) is larger than along said second direction (X2) .

5. The security document of any of the preceding claims wherein, at locations where an edge of said foil element (5) does not coincide with an edge of said substrate (1), said counter layer (8) laterally extends by a non-zero distance (D) beyond said foil element (5).

6. The security document of claim 5, wherein said non-zero distance (D) is at least 0.5 mm, in particular at least 1 mm.

7. The security document of any of the preceding claims wherein a density (p) of said counter layer (8) gradually decreases across at least one edge (10c, lOd) of said counter layer (8) .

8. The security document of claim 7 wherein a local density (p) of said counter layer (8), averaged over a circular area of diameter d, gradually decreases across at least one edge (10c, lOd) of said counter layer (8) over a width E > 2-d, from a maximum value to zero, for at least one diameter d between 0.5 and 5 mm.

9. The security document of any of the pre^¬ ceding claims wherein said counter layer (8) is transparent or translucent or has the same colour as said sub- strate (1) .

10. The security document of any of the pre^¬ ceding claims further comprising at least one print layer (12) on said second side (7), wherein said print layer (12) is located above said counter layer (8) .

11. The security document of claim 10 wherein said print layer (12) is applied onto said counter layer (8) and covers at least 50%, in particular at least 90% of said counter layer (8).

12. The security document of any of the claims 1 to 9 further comprising at least one print layer (12) on said second side (7), wherein said print layer (12) is located below said counter layer (8) and, in particular wherein said print layer (12) is at least par^¬ tially covered by said counter layer (8) .

13. The security document of any of the claims 10 to 12 wherein said print layer (12) is an off^¬ set print layer.

14. The security document of any of the claims 10 to 13 further comprising a varnish layer (14), in addition to said counter layer (8), which varnish layer (14) covers at least part of said print layer (12) and said counter layer (8) and extends over a larger area than said counter layer (8).

15. The security document of any of the pre- ceding claims wherein every part of said foil element (5) is laminated to said substrate (1) .

16. The security document of any of the preceding claims wherein said counter layer (8) has a spe^¬ cific weight per surface area of at least 10

.

17. The security document of any of the pre- ceding claims wherein said foil element (5) has a thickness of at least 5 μτη, in particular between 5 - 20 um or of at least 20 μιη.

18. The security document of any of the preceding claims wherein said counter layer (8) covers at least 95%, in particular at least 99%, in particular 100% of the foil element area.

19. The security document of any of the pre^¬ ceding claims wherein said counter layer (8) is IR ab^¬ sorbing and/or fluorescent.

20. The security document of any of the pre^¬ ceding claims wherein said counter layer (8) comprises surface structures (19) having a lateral size (L) between 5 and 1000 pm, in particular between 10 and 500 μιη.

21. The security document of any of the pre- ceding claims wherein at least one of said foil element

(5) and said counter layer (8) is embedded at least partially in a recess (20, 21) of said security document.

22. The security document of any of the preceding claims wherein said substrate (1) comprises an opening (23) extending through said substrate at a location of said foil element (5), wherein said foil element (5) and said counter layer (8) span said opening (23) .

23. The security document of any of the preceding claims wherein said substrate (1) is a multi-layer substrate comprising first and second outer substrate layers (25a, 25b) and one or more central substrate lay^¬ ers (26) arranged between said outer substrate layers (25a, 25b), wherein an opening (27) is formed through at least one of said outer substrate layers (25a, 25b) but not through at least one of said one or more central substrate layers (26) , and wherein said foil element (5) and said counter layer (8) span said opening (23) .

24. A method for manufacturing the security document of any of the preceding claims comprising the steps of applying said foil element (5) to said first side (6) and said counter layer (8) to said second side (7) .

25. The method of claim 24 wherein said counter layer (8) is applied by applying a UV hardening com^¬ position to said second side (7) and by hardening said composition by UV radiation.

26. The method of any of the claims 24 or 25 comprising the step of applying said counter layer (8) by means of screen printing.

27. The method of any of the claims 24 or 25 comprising the step of applying said counter layer (8) as a foil element to said second side (7), in particular using lamination or hot stamping.

28. The method of any of the claims 24 to 27 comprising the step applying an offset print (12) on top of said counter layer (8).

29. The method of any of the claims 24 to 28 wherein said foil element (5) is applied to said sub^¬ strate (1) after said counter layer (8) is applied to said substrate (1).

30. The method of any of the claims 25 to 29 comprising the step of forming surface structures (19) on said counter layer (8) by means of ink-jet printing.

31. The method of claim 30 wherein said sur^¬ face structures (19) have a lateral size (L) between 5 and 1000 pm, in particular between 10 and 500 μιτι.