RU2680329C9 - Security sheet or document having one or more enhanced watermarks - Google Patents

Abstract

FIELD: manufacturing technology.SUBSTANCE: invention relates to a security sheet or document having one or more enhanced watermarks. In one typical embodiment, the inventive security sheet or document is a single-ply paper that is made up of a paper layer including one or more watermarks, and a micro-optic security device (e.g., a patch or thread) that at least partially covers an upper or face portion of the watermark(s). Overlying patch or thread increases the durability of the watermark(s), thereby allowing for the watermark(s) as well as reduced fibre density areas therein to be made larger, and further allowing for the reduced fibre density areas to be made thinner. In a preferred embodiment, the micro-optic security device projects one or more synthetic images that coordinate or link in with the watermark design(s). In a more preferred embodiment, the micro-optic security device offers a machine detectable/readable feature in the form of enhanced IR-brightness, especially when measured in transmission.EFFECT: as will be readily appreciated, the inventive security sheet or document offers greatly improved counterfeit-resistance.12 cl, 11 dwg

Description

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a partial continuation of U.S. Patent Application No. 12 / 997,390, filed February 23, 2011, and claims priority for U.S. Patent Application No. 61 / 911,141, filed December 3, 2013, and U.S. Patent Application No. 61 / 911,831, filed December 4, 2013, US Provisional Patent Application No. 61 / 911,885, filed December 4, 2013, and US Provisional Patent Application No. 61 / 924,000, filed January 6, 2014, each of which is incorporated herein by reference in full volume.

FIELD OF THE INVENTION

The invention generally relates to a security sheet or document having one or more reinforced watermarks.

BACKGROUND AND SUMMARY OF THE INVENTION

Security papers are used to make security documents, such as banknotes, passports, postage stamps, etc. Traditionally, a wide variety of security features are incorporated into or provided on such security papers. Known examples of such security features include watermarks, inserted and windowed security threads, fluorescent pigments, and the like.

Watermarks, which are recognizable images or structures on paper that look like different shades of light / dark when viewed in transmitted light or in reflected light against a dark background, have been protecting against forged documents for hundreds of years. In fact, watermarks and their catchy design are the most easily recognizable security features among the general public for authenticating security documents such as banknotes.

However, there is still a need to improve the security or counterfeiting of watermarked security documents.

The present invention responds to this need by providing enhanced, and therefore more resistant to fake, watermarks in paper products and similar materials. In particular, the present invention provides a security sheet or document having one or more reinforced watermarks, the sheet or document including:

fiber sheet material comprising one or more watermarks, each watermark having one or more first sections with a reduced fiber density relative to the surrounding sections of the fiber sheet material and one or more second sections with a similar or increased fiber density relative to the surrounding sections of the sheet material, each watermark has an upper or front part and a lower or rear part; and

means for enhancing one or more watermarks, making them visually enhanced, machine detectable / readable, or giving both of these properties, the aforementioned means being selected from the group that includes:

a) one or more film-like or foil-like protective elements, at least partially covering the front or back of one or more watermarks, one or more film-like or foil-like protective elements provided in the form of a tape, strip, thread or flap;

b) one or more other than film-like and foil-like security elements contained in / in either or both of one or more first sections and one or more second sections of one or more watermarks, wherein one or more security elements are selected from the group to which relate:

i. recognizable or distinguishable characters; and

ii. one or more substances that add color and / or are machine-readable or machine-readable, including but not limited to reacting to ultraviolet (UV) or infrared (IR) rays, luminescent (i.e., fluorescent or phosphorescent), thermochromic, photochromic electrochromic, metal or magnetic protective fibers, markers, confetti, dyes, pigments;

c) one or more polymeric or resin materials contained in one or more first regions and, optionally, one or more second regions of one or more watermarks, wherein one or more polymer or resin materials have a refractive index or a combined (final) refractive index essentially similar to cellulose;

d) optionally a windowed second paper layer covering the front or back of one or more watermarks; and / or

e) one or more transparent or translucent areas surrounding each of one or more watermarks.

In a first exemplary embodiment, the security sheet or document of the invention is a single or multi-ply paper that includes:

a first paper layer comprising one or more watermarks, each surface of the paper layer having an upper or front part of the watermark (s) or its (lower) back or back;

one or more film-like or foil-like protective elements that at least partially cover the upper or front part or the lower or back part of one or more watermarks; and optionally

a second paper layer having a reduced grammage compared to the first paper layer, and optionally one or more through windows, the second paper layer covering the upper or front part or the lower or rear part of one or more watermarks.

The film-like or foil-like security element preferably has a color different from the color of the watermark (s) and surrounding paper, which enhances the general appearance of the watermark (s) below or above it, and also enhances the contrast between the watermark (s) below (or) under it or above it and the surrounding paper.

In one such embodiment, the film-like (e) or foil-like (e) security element (s) is (are) a micro-optical security device projecting one or more synthetic images, such as the MOTION ™ micro-optical security device described, for example, U.S. Patent No. 7,333,268. Such devices exhibit color images on a transparent or slightly colored background and are thus well suited for use in combination with the printed information below them. It has been observed that these protective devices provide watermark (s) that look like multi-tone. A person skilled in the art will easily understand that multi-ton watermarks pose an even more difficult task to the counterfeiter.

In a preferred embodiment, the micro-optical protective device is provided in the form of a patch applied to the surface that completely or partially (for example, half) covers the watermark, the watermark containing one or more polymer or resin materials within the first and / or second sections of the watermark, one or more polymeric or resin materials have a refractive index or a combined (final) refractive index, essentially similar to that of cellulose. In one such embodiment, the site also includes one or more features selected from the group that includes areas with increased fiber density in the form of recognizable or distinguishable signs, one or more substances that impart color, and one or more so-called protective features of the second levels that are machine-detectable or machine-readable (for example, reacting to UV or IR rays, fluorescent, thermochromic, photochromic, electrochromic, metal or magnetic shields nye fibers, markers, confetti, dyes, pigments).

One skilled in the art will readily appreciate that the micro-optical security device may also be in the form of an elongated protective tape, strip or thread applied to the surface, or a partially inserted elongated protective tape, strip or thread present in the window portions of the second paper layer (i.e. window thread).

Micro-optical devices, such as the MOTION ™ device, can be designed in such a way that when they match the watermark (s), the synthetic images they project are combined with the design (s) of the watermark. For example, in the above embodiment, the synthetic image (s) formed by each patch may be coordinated or associated with the design (s) of the watermark. Synthetic image (s) may also complete the design (s) of the watermark or be located within the design (s). As described in more detail below, it may be a one-way or two-way sign.

In another similar embodiment, the micro-optical protective device (s) also described (for example, in US Pat. No. 7,333,268) show color images (of any color, including white and black) against a translucent or substantially opaque background of another colors. In this embodiment, the micro-optical security device (s) at least partially cover (s) and visually camouflage (s) the upper or front part of one or more watermarks or the lower or back part of one or more watermarks . The watermark (s) do not visually differ in reflected light from the coated side of the paper layer, but are visually visible in reflected light from the uncoated side of the paper layer and in transmitted light from both sides of the paper layer.

A characteristic advantage of typical embodiments of the present invention in which a partially or fully overlying or underlying film-like or foil-like security element, such as a MOTION ™ security device, is used is the increased durability of each watermark. As is well known to specialists in this field, one of the basic requirements for banknotes and other security documents is that the document and its security features must withstand the effects of walking. These documents / features must be durable (i.e. resistant to kinks, tears and contamination) and resistant to moisture and chemical absorption. Full or partial coating of the watermark (s) with a film, foil, tape, strip, thread or patch is used to physically protect the watermark (s) from damage during walking and handling and, thus, increases them durability.

Due to the increased durability provided for these watermarks, it was determined that these watermarks can be made in a larger size, and the total area within each watermark occupied by sections with a reduced fiber density (i.e., first sections) can be increased, and these sections can even be made with a smaller thickness. In particular, it was found that these sections with a reduced fiber density can be made with a thickness of from 10 to 15 microns with a total thickness of from about 10 to about 60 microns. The total area occupied by these areas with a reduced fiber density within each such watermark is from about 5 to about 75% of the total watermark area, preferably from about 20 to about 60%. In addition, the total area occupied by each similar watermark within a banknote of approximately 10,000 mm ² may be from about 5 to about 25%, which means an increase in size compared to traditional watermarks of about 5%.

The inventors of the present invention also made an unexpected discovery, according to which micro-optical devices, such as the MOTION ™ device, can also provide a detectable / readable feature in the form of enhanced IR brightness, in particular when measured in transmitted light. The term "enhanced IR brightness" in the context of this description means the level of IR transmittance is at least 5% greater (preferably more than 10% greater) than the IR transmittance of the background paper. The IR transmittance is measured by using an optical sensor with a sensitivity of 830 nanometers (nm) or more and by projecting an IR light source with a wavelength of more than 800 nm through the sample. To make IR brightness a reliable machine-readable feature, a micro-optical device is preferably fabricated using one or more IR transparent elements (e.g., IR-transparent ink) that do not contain IR-absorbing elements (e.g., IR-absorbing inks). Also, preference is given to the absence of infrared absorbing elements in areas close to the device on the front and back of the paper (s) layer (s). In one such embodiment, the micro-optical device is a security thread (e.g., a MOTION ™ security thread) that does not contain IR absorbing elements. In this embodiment, the micro-optical security thread is made using IR-transparent ink (for example, ink comprising non-absorbing IR pigments and / or dyes) for micro-printing, and areas on the front and back of the paper (s) layer (s) within at least two-thirds (2/3) of the length of the security thread does not contain IR absorbing elements.

In addition to at least a partially overlying or underlying micro-optical device, one or more additional security features may be contained on / within the first and / or second sections of one or more watermarks. In one such embodiment, the watermark (s) do not contain one or more polymeric or resinous materials within the first and / or second sections. Additional security features are selected from the group that includes areas with increased fiber density in the form of recognizable or distinguishable characters, one or more color-giving substances, and one or more second-level security features that can be detected or read by machine, as described above.

In a second typical embodiment, the security paper according to the invention is a multilayer paper, including:

a first paper layer having a reduced grammage (for example, from about 10 to about 50 grams per square meter (g / m ² )) and comprising one or more watermarks, each surface of the first paper layer showing the top or face of one or more watermarks signs or its (their) lower or back part; and

a second paper layer having a reduced grammage (for example, from about 10 to about 50 g / m ² ) and optionally one or more through windows, the second paper layer covering either the surface of the first paper layer showing the upper or front part of one or more a watermark, or a surface showing the bottom or back of one or more watermarks.

In one such embodiment, the second paper layer is a window, one or more through windows in the second paper layer coinciding with the upper or front part or the lower or rear part of one or more watermarks. Thanks to this typical embodiment, the use of two paper layers and, optionally, one or more overlying or underlying through windows, allows greater contrast between one or more watermarks and the background. One or more overlying or underlying through windows operate on a principle similar to electrotype, occupying areas without paper or areas with thinner paper, resulting in areas that are brighter than the background in each section of paper / watermark.

In a third typical embodiment, one or more security elements in the form of one or more coloring agents are contained within the first and / or second portions of one or more watermarks. One or more coloring agents include both dyes and pigments (for example, ultrafine pigments). In this embodiment, the security sheet or document does not include one or more film-like or foil-like security elements. The resulting watermarks have a tonality (i.e., a color scheme or gradation of tones) in a color or shade different from the main portion of the material surrounding the watermark. Watermarks according to the invention serve to enhance the perception and resistance to imitation of existing watermarks.

In a fourth exemplary embodiment, one or more polymeric or resin materials are contained within the first (s) region (s) and, optionally, the second (s) region (s) of one or more watermarks. As indicated above, the security sheet or document in this typical embodiment does not include one or more film-like or foil-like security elements. The first and / or second sections in this embodiment may also contain one or more security features selected from the group that includes areas with increased fiber density in the form of recognizable or distinguishable signs, one or more substances that impart color, and one or several security features of the second level, which are machine detectable or machine readable, as described above.

In a fifth exemplary embodiment, the security sheet or document of the invention is a single-layer paper including:

a paper layer comprising one or more watermarks; and

one or more transparent or translucent areas in the paper layer surrounding each of one or more watermarks, which thus frame, and therefore enhance the visual perception of, the watermark (s).

Other features and advantages of the invention will become apparent to a person skilled in the art from the following detailed description and the attached figures.

Unless otherwise defined, all technical and scientific terms used by the authors have the meaning generally accepted among specialists in the field to which this invention relates. All publications, patent applications, patents and other sources mentioned by the authors are incorporated by reference in full. In case of disagreement, the present description, including definitions, shall prevail. In addition, the materials, methods / processes and examples are illustrative only and do not limit the scope of the invention.

BRIEF DESCRIPTION OF THE FIGURES

The present invention will be better understood with reference to the following figures. The components in the figures are not necessarily shown to scale, but the focus is on a clear explanation of the principles of the present invention. Although typical embodiments are disclosed in connection with the figures, the present invention is not limited to the embodiment or embodiments described (and) by the authors. On the contrary, the goal is to cover all alternatives, modifications and equivalents.

Specific features of the disclosed invention are explained with reference to the accompanying figures, among which:

FIG. 1 is a watermark image (30 shield) with an overlying MOTION ™ protective patch on / in the exemplary security paper observed in daylight (reflected light from the visible spectrum) and in infrared transmission light from the front or front side of the security paper , with a watermark and a patch, shown for clarity on an enlarged scale;

FIG. 2a is another image of FIG. 1 watermark with an overlying protective patch, which is also observed in daylight (reflected light of the visible spectrum) and in infrared transmitted light from the front of the security paper, the image is enlarged, but to a lesser extent than in FIG. 1, while FIGURES 2b-d are enlarged images of the same watermark with an overlying protective patch shown — in IR transmitted light from the back of the security paper (FIG. 2b), in IR reflected light from the front of the security paper (FIG. . 2c) and in IR reflection from the back of the security paper (FIG. 2d);

FIG. 3a is another image of FIG. 1 watermark with an overlying protective patch observed in daylight (reflected light of the visible spectrum) from the front of the security paper, the image is enlarged, but to a lesser extent than in FIG. 1, while FIGURES 3b-d are enlarged images of the same watermark with an overlying protective patch shown — in the reflected light of the visible spectrum from the back of the security paper (FIG. 3b), in the transmitted light of the visible spectrum from the front of the security paper (FIG. 3c) and in transmitted light of the visible spectrum from the back of the security paper (FIG. 3d);

FIG. 4 is a schematic diagram of a modified long mesh paper machine or a double mesh paper machine with which watermarks are included along the machine direction of the forming paper web through a leveling roller, and by which a security element in the form of an elongated security thread is applied to the surface of the paper web with watermarks in front of section of the machine for humidification under pressure. In the machine, means are used to combine watermarks in the machine direction and an elongated security thread on a paper web. This method of manufacturing the sheet material according to the invention does not eliminate the distribution of fibers, resulting in a greater distribution of fibers with increased density and rigidity of the substrate, which allows to resist deformation, distortion and bending of the protective thread;

FIG. 5 is a schematic diagram of another modified long-mesh paper machine or double-mesh paper machine, with which an elongated security thread is fed to the surface of the fiber web at the same time or just before the watermark (s) are included in it and before the section of the pressure wet machine . In the machine, means are used to combine in the machine direction the elongated security thread and the watermark (s) on the paper web. This method of manufacturing a fiber sheet material according to the present invention leads to the flow of fibers around the filament, which results in the distribution of fibers with a lower density with reduced density and stiffness under the surface applied to the filament;

FIG. 6 is a schematic diagram of a paper machine consisting of two cylinder paper machines interconnected by a receiving cloth, where an elongated security thread is in contact with a watermarked paper web formed by one cylinder paper machine before connecting to a second paper web formed by another cylinder paper machine . This machine also uses means for combining in the machine direction an elongated security thread and watermark (s) with the first paper web;

FIG. 7 is a direct comparison of enlarged watermark images of the state of the art and of a typical embodiment of an enhanced watermark according to the invention, with extraordinary brightness and intensity;

FIG. 8 is a direct comparison of enlarged images of a typical embodiment of a watermark according to the invention, which uses a second level security feature excited in the UV region both in transmitted light and under UV light;

FIGURES 9a, b are schematic views showing a method of manufacturing a typical embodiment of a security paper document according to the present invention;

FIG. 10 is an enlarged image of a fiber mat or sheet in a wet state on a paper machine (observed in reflected light against a dark background) with the removal of paper pulp in selected sections of the sheet, resulting in a decrease in fiber density in these selected sections. Selected sections are round in shape and shown in two different sizes, with larger selected sections also including a circular region of higher fiber density; and

FIG. 11a, b are enlarged images of a circle enclosed in a selected portion shown in FIG. 10 (observed in transmitted light) after treatment with one or more polymeric or resin materials having a refractive index or combined refractive index, essentially similar to that of cellulose. The first enlarged image (FIG. 11a) shows a circular region within a selected portion having a color similar to the color of the surrounding fiber mat or sheet, while the second enlarged image (FIG. 11b) shows that the printing material observed in this typical embodiment The security element of the invention is easy to read.

DETAILED DESCRIPTION OF THE INVENTION

Thanks to the present invention, watermarks formed on / in the security sheet or document are enhanced, making the security sheet or document more resistant to tampering.

A sheet or document according to the invention, as noted above, includes: a fiber sheet material comprising one or more watermarks; and means for enhancing one or more watermarks, making them visually enhanced, machine detectable / readable, or giving both of these properties.

Fibrous sheet materials suitable for use in accordance with the present invention are paper or similar paper sheet materials. These sheet materials, which are single or multilayer sheet materials, can be made of various types of fibers, including synthetic or natural fibers, or a mixture thereof. For example, these sheet materials can be made from fibers such as abacus, cotton, linen, wood pulp, and mixtures thereof. As is well known to those skilled in the art, cotton blends of cotton / flax or cotton / synthetic fiber are preferred for banknotes, while wood pulp is typically used in security documents other than banknotes.

Watermarks can be formed in a fiber sheet material using known methods and techniques. For example, a watermarked sheet material can be made on a round-mesh paper machine (using embossed wire cloth or by applying a thin piece of metal, usually in the form of an image or letter, onto a wire cloth), or on a long-mesh paper machine (using a leveler )

The following discusses typical embodiments of a security sheet or document according to the invention, in which various means of enhancing the watermark (s) are applied, and corresponding methods for their manufacture.

In a first exemplary embodiment, the security sheet or document of the invention is a single or multi-ply paper that includes (a) a first paper layer comprising one or more watermarks, each surface of the paper layer having an upper or front watermark (s) or its lower or rear part (b) one or more film-like or foil-like protective elements having a color different from the watermark (s) that at least partially cover the upper or itsevuyu part or the lower or rear part of the water (s) of the mark (s), and optionally (c) a second paper layer having a smaller grammage than the first paper layer, (e.g., from about 10 to about 50 g / m ² ) and, optionally, one or more through windows, the second paper layer covering the upper or front part or the lower or rear part of the watermark (s).

The film-like (e) or foil-like (e) protective (s) element (s) used to practice the present invention are limited only by their film-like or foil-like structure, the structures provided having a total thickness of from about 15 to about 100 microns (preferably from about 15 to about 50 microns). Film-like or foil-like structures can take any form, including, but not limited to, the form of ribbons, stripes, threads or patches. They can demonstrate or project information perceived by a person either directly or using a device, and / or contain information recognized / read by the machine. Structures can be segmented into sections, the information being displayed or projected or otherwise contained in some or all of these sections, which are the same or different.

In suitable film-like or foil-like protective elements, one or more of the following elements can be used: demetallized or selectively metallized, magnetic, combined magnetic and metal, or embossed (for example, made by means of blind embossing) areas or layers that change the color of the coating, consisting of materials with a color shear, iridescent, liquid crystalline, photochromic and / or thermochromic materials, coatings of luminescent and / or magnetic materials, holographic and / or diffraction ktsionnye security features and micro-optical security features.

In a preferred embodiment, the protective element (s) are a micro-optical structure. As noted above, such structures project one or more synthetically enlarged optical images and typically include: (a) a photoconductive polymer substrate; (b) a plurality of micro-sized pictograms located on / in the polymer substrate; and (c) a variety of microlenses. The plurality of pictograms and microlenses are configured in such a way that in the case where a plurality of pictograms is observed through the plurality of microlenses, one or more synthetically enlarged images are projected. These projected images can exhibit many different optical effects. Such structures are described in US Pat. No. 7,333,268 to Steenblik et al., US Pat. No. 7,468,842 to Steenblik et al. US Pat. No. 7,738,175 to Steenblik et al., International Patent Publication WO 2005/106601 A2, Commander et al. and International Patent Publication WO 2007/076952 A2, Kaule et al. In one such embodiment, the micro-optical structure used is described in US Pat. No. 7,333,268 to Steenblik et al. (e.g., a MOTION ™ micro-optical protective device), the structure being formed from a polymer substrate made using one or more essentially colorless polymers selected from the group including, but not limited to, polyester, polyethylene, polyethylene terephthalate, polypropylene, polyvinyl carbonate, polyvinylidene chloride and their combinations.

In a more preferred embodiment, the micro-optical protective device is provided in the form of a patch applied to the surface of the patch to completely or partially cover (for example, half) the watermark, the watermark comprising one or more polymer or resin materials within the first and / or second sections, one or several polymer or resin materials have a refractive index or a combined (final) refractive index that is essentially similar to that of cellulose. The first and / or second sections of the watermark may also contain one or more features selected from the group that includes areas with increased fiber density in the form of recognizable or distinguishable signs, one or more substances that impart color, and one or more security features second level, which are machine detectable or machine readable, as described above.

In another more preferred embodiment, the micro-optical security device is provided in the form of an elongated strip or thread applied to the surface, or a partially inserted elongated protective strip or thread that is present in the window portions of the second paper layer (i.e., the window thread). The strip or thread in this embodiment completely or partially covers the watermark (s).

In yet another preferred embodiment, the micro-optical security device (for example, the MOTION ™ device) is designed so that when they match the watermark, the synthetic images they project are combined with the watermark design. For example, in the above embodiments, the synthetic image (s) formed by each patch or thread can be coordinated or connected to a watermark design. Synthetic image (s) may also complete the design (s) of the watermark or be located within the design (s). This can be a one-way or two-way sign. In other words, the complete information transmitted to the observer is not provided only through a watermark or synthetic image (s), but requires that they be visible at the same time. In one such example, when viewed from an optimal (perpendicular) angle of view using transmitted visible light, the MOTION ™ patch projects a synthetic image in the form of a heraldic shield superimposed (coincidently) on the design of a watermark in the form of a shield. If the angle of view is shifted from the axis, the synthetic image and the design of the watermark cease to coincide with each other, and the design of the watermark (shield and number 30) is visible within the patch, and the synthetic image is moved or switched from a heraldic shield, for example, to many images of numbers .

A characteristic advantage in typical embodiments of the present invention in which a partially or fully overlying or underlying film-like or foil-like security element, such as a MOTION ™ micro-optical security device, is used is the increased durability of each watermark. Coating all or part of the watermark (s) with a film, foil, tape, strip, thread or patch is used to physically protect the watermark (s) from damage during walking and handling, thereby increasing their durability .

Due to the increased durability provided for these watermarks, it was determined that these watermarks can be made larger and that the total area within each watermark occupied by areas with a reduced fiber density (i.e., first sections) can be increased, and these sections can even be made with a smaller thickness. In particular, it was found that these sections with a reduced fiber density can be made with a thickness of from 10 to 15 microns, with a total thickness of from about 10 to about 60 microns. The total area occupied by these areas with reduced fiber density within each such watermark is from about 5 to about 75 percent (%) of the total watermark area, preferably from about 20 to about 60%. In addition, the total area occupied by each similar watermark within a banknote of approximately 10,000 mm ² can be from about 5 to about 25%, which means an increase in size compared to traditional watermarks by about 5%.

The inventors of the present invention also made an unexpected discovery that micro-optical devices, such as a MOTION ™ device, can also provide a machine-detectable / readable feature in the form of enhanced IR brightness, especially when measured in transmitted light. To make IR brightness a reliable machine-readable feature, preference is given to making a micro-optical device using one or more IR-transparent elements (e.g., IR-transparent ink) without the presence of IR-absorbing elements (e.g., IR-absorbing inks). Also, preference is given to the absence of infrared absorbing elements in areas close to the device on the front and back of the paper (s) layer (s).

In FIG. 1 shows one such embodiment of a security sheet or document according to the invention, indicated by a conventional number 10). The micro-optical device is a protective patch MOTION ™ 12, which does not contain infrared absorbing elements. The patch 12 is located above the watermark 14 in the form of a shield in which the dark areas formed by more densely laid fibers compared to the normal density of the warp fibers (i.e., the second sections) 16 occupy the outer perimeter, the light areas formed by less densely laid fibers, compared with the normal density of the warp fibers (i.e., the first sections) 18, occupy the area inside the shield design, and the area occupied by the number 30 forms even brighter or less dense areas. Watermark 14 with an overlying protective patch MOTION ™ 12 in FIG. 1 is shown in daylight and in infrared transmittance, with the watermark and patch shown on an enlarged scale for clarity.

As will be easily understood from FIG. 1, the number 30 is very bright as a result of having an overlying patch. In this case, IR brightness correlates with the strength of the IR signal, which, as noted above, is measured in transmitted light by using an optical sensor with a sensitivity of 830 nm or higher and by projecting an IR light source with a wavelength of more than 800 nm through the sample. IR brightness can be controlled by the IR properties of the ink used for micro-printing of the protective patch 12. Micro-printing in the form of micro-sized pictograms located on / in the polymer substrate is performed using a printing method (for example, inkjet, laser, high, flexographic, gravure, gravure printing and sublimation printing), or using a microstructural approach. In the latter case, the pictograms should be made as voids or grooves in the substrate (for example, grooves with a total depth, for example, from about 0.5 to about 8 microns), or as relief structures relative to the substrate (for example, relief structures (colored or colorless) with total height, for example, from about 0.5 to about 8 microns). An IR transparent material is used (for example, a paint including non-absorbing IR pigments and / or dyes) to form pictograms, for example, by printing, coating or partially or completely filling the grooves or areas surrounding relief structures, or forming relief (color or colorless) ) structures. In a preferred embodiment, the areas on the front and back of the paper layer (s) within a distance of about 5 millimeters from the outer edge of the patch should not contain IR absorbing elements.

With respect to the appearance of the embodiment of FIG. 1, and as shown in FIGURES 2a-d and 3a-d:

(a) In the IR transmission or IR transmission from the front or front side of the document, you can see a watermark (shield and number 30) and a faded patch (see FIG. 2a);

(b) In IR transmission from the back of the document, you can see a watermark (shield and number 30) in the reverse image and a darker patch applied (see FIG. 2b);

(c) In the infrared light from the front of the document, you can see a watermark (only the outline) and a pale patch applied (see FIG. 2c);

(d) In the IR reflection from the back of the document, neither a watermark nor a patch can be seen (see FIG. 2d);

(e) In the reflected light of the visible spectrum from the front of the document, one or more synthetic images can be seen, but not a watermark (or just a pale outline of a watermark) (see FIG. 3a);

(f) In the reflected light of the visible spectrum, a dark watermark can be seen from the back of the document (see FIG. 3b);

(g) In the transmitted light of the visible spectrum from the front of the document, you can see a combined image of a watermark and one or more synthetic images (see FIG. 3c); and

(h) In the transmitted light of the visible spectrum from the back of the document, you can see a watermark (shield and number 30) in the reverse image with a color patch applied, but not projected synthetic image (s) (see FIG. 3d )

As mentioned above, in addition to at least partially overlying or underlying micro-optical device, one or more additional security features may be contained on / within the first and / or second sections of one or more watermarks. In one such embodiment, the watermark (s) do not contain one or more polymeric or resinous materials within the first and / or second sections. Additional security features are selected from the group that includes areas with increased fiber density in the form of recognizable or distinguishable characters, one or more color-giving substances, and one or more second-level security features that can be detected or read by machine, as described above.

The following describes methods and technologies for performing the first typical embodiment, in which a fiber sheet material with a film-like or foil-like protective element is combined in the machine direction (MD) with one or more watermarks that are contained or formed in the sheet material.

Film-like or foil-like security elements can be inserted (if, for example, in the form of a protective strip or thread) into the second paper layer or deposited on the surface of a watermarked paper layer or in the second paper layer (if, for example, in the form of a thread or patch) using known methods and technologies. For example, the protective element (s) (with one or more adhesive layers) can be transferred onto the surface of a watermarked or second paper layer as a transfer film using methods that include mechanical, chemical, thermal and photo-induced separation. The idea of separating the necessary components from the carrier substrate is known to those skilled in the art of transferring a holographic foil and consists in coating (e.g., optical) and adhesives on a film with a release coating (e.g., a coating layer) so that the coatings and adhesives could be transferred to the final substrate using heat and pressure. This approach is particularly suitable for applications requiring films with a very thin section.

Activated adhesives are used to fasten or bond film-like or foil-like security elements to the surface of a fiber sheet material. Suitable adhesives are not limited to specific materials, and include adhesives activated under the influence of water, heat and / or pressure, activated in a secondary drying section of a paper machine, in which the temperature reaches 100-160 ° C. These coatings may be applied in the form of solvent based polymer solutions or aqueous solutions or dispersions. Suitable dispersions are selected from the group which includes dispersions of acrylic resin, dispersion of epoxy resin, dispersion of natural latex, dispersion of polyurethane resin, dispersion of polyvinyl acetate resin, dispersion of polyvinyl alcohol resin, dispersion of urea-formaldehyde resin, dispersion of vinyl acetate resin, dispersion of ethylene vinyl acetate, ethylene vinyl alcohol dispersion dispersions of polyester resin and mixtures thereof.

The machine-directional combination of protective patches with the watermarks contained or formed in the sheet material can be achieved by indexing the relative position of the watermark (s) on the equipment used to create the watermark (s) in the sheet of paper. Then, the position of the watermark (s) (s) is continuously transferred to the equipment used to apply the protective patch (s) to the surface of the paper. The pre-applied signs or signs on the carrier film used to transfer the patch (patch) are used to control the speed of the carrier film, and hence the patch (patch), thus ensuring the combination of the watermark (s) with the patch (s).

The combination in the machine direction of the security thread with the watermarks contained or formed in the sheet material is hereinafter described in connection with FIGURES 4 through 6.

In FIG. 4 shows a process in a long mesh paper machine for producing a single layer embodiment of a fiber sheet material according to the present invention. In this process, the adhesive coated security thread 20 (oriented so that the front side of the security thread, and not the adhesive coated back, is the topmost layer) is guided through the pipe 22 by a speed-promoting mechanism 24 (e.g., an electric servo mechanism with a servo drive) and pushed onto the surface of a partially frozen propellant fiber web 26 (e.g., a fibrous suspension containing from about 1 to about 10 wt.% of the starting material and from about 99 d approximately 90 wt.% water) in the wet part 28 of the paper machine after watermarking the web 26 with the help of the leveling roller 30. In this case, the security thread 20 may be located partially or completely above the watermark (s) (s) ( that is, layered security features) of the surface of the web 26. One skilled in the art will readily appreciate that the leveling roller 30 can be provided with protruding and / or recessed areas on its surface that can completely or partially overlap an area on the surface 26 paintings, which will be occupied by a thread 20.

It should be noted that this embodiment of the method according to the invention does not serve to disrupt the distribution of fibers around the protective thread applied to the surface, resulting in the distribution of higher density fibers with increased density and stiffness of the substrate, which allows to resist deformation, distortion and bending of the protective thread.

As water is drained from the web 26 around the yarn 20, fibers are formed that hold it on the front or top surface of the web 26. After exiting the wet portion 28, the fiber web 26 passes through the press, the main and secondary drying section, and the calender section of the paper machine. Staying in the secondary drying section of the paper machine, the web 26 is exposed to temperatures and / or pressure sufficient to activate the adhesive coating of the security thread, causing the fiber to bond firmly to the fiber sheet material, the security thread being constantly open on the front or top surface of the sheet material, partially or completely covering the formed (s) watermark (s), staying out of sight on the back or bottom surface of the sheet material.

The combination in the machine direction of the protective thread 20 with the formed (and) water (s) sign (s) is achieved using traditional technologies common in this field. For example, as best shown in FIG. 4, an automatic alignment control system for a paper machine is used, including an advance mechanism 24 for a variable speed security thread, optical sensors 32a, 32b for tracking alignment marks on the leveling roller 30 and the security thread 20, and a coding disk 34 for monitoring the paper forming speed on the car.

As the forming web 26 passes through the wet portion of the paper machine 28, alignment marks located on the leveling roller 30 and the security thread 20 are continuously monitored by the optical sensors 32a, 32b, thereby continuously detecting / monitoring the position of the security thread 20 fed through the pipe 22 and the advance mechanism 24, and the position of the watermark (s) (s) relative to the edge of the forming web 26, and the speed of the forming paper is monitored by the coding disk 34. Signals for determining the position and orosti, and the speed and position advancing mechanism 24 are regulated on the basis of these signals in such a way that the security thread 20 and the water (s) point (s) were combined along the machine direction of the web 26.

In another embodiment of the method according to the invention, which is shown in FIG. 5, the adhesive coated security thread 20 (also oriented so that the security thread, rather than the adhesive coating, is the topmost layer) is guided through a speed-promoting mechanism 24 and through an optical sensor 32b, and then pushed onto the surface of a partially solidified formed fiber the web 26 by the leveler 30 in the wet part 28 of the paper machine, the leveler 30 simultaneously or sequentially forming watermarks on the web 26. It should be noted that due to this embodiment of the method according to the invention, the fibers flow around the security thread, which results in the distribution of fibers with a lower density with reduced density and stiffness of the substrate under the thread.

Similar to the above option, when moving the forming web 26 through the wet part 28 of the paper machine, alignment marks located on the leveling roller 30 and the security thread 20 are continuously monitored by optical sensors 32a, 32b, thereby continuously detecting / monitoring the position of the watermark (s) (s) and the position of the security thread 20 applied to the surface of the web 26, relative to the edge of the forming web 26, and the speed of the forming paper is monitored by the coding disk 34. Signals are generated The position and speed, and the speed and position of the advance mechanism 24 are adjusted based on these signals so that the security thread 20 and the watermark (s) are aligned along the machine direction of the web 26.

A round-mesh process for manufacturing a two-layer embodiment of a fiber sheet material according to the present invention is shown in FIG. 6. In this process, which uses two cylinder paper machines 36a, 36b, connected by a receiving cloth 38, two paper sheets 40, 42 are formed at the same time, pressed against each other in the area of the roller 44, and then fed together to the press, drying and calendering sections of the paper machine. The resulting fiber sheet material has the same physical characteristics as those described above for sheet materials manufactured using a long mesh paper machine process. A person skilled in the art will easily understand that, although in FIG. 6 shows wet-paper cylinder paper machines, dry-cylinder cylinder paper machines can also be used to make the fiber sheet material of the present invention.

The two-layer paper web 46 formed by the cylinder paper machines shown in FIG. 6 has a recessed adhesive-coated security thread 20 and one or more watermarks formed on its surface, the security thread 20 and watermark (s) being completely visible from this surface. Watermark (s) are formed in the paper web 40 by the forming cylinder 48, then the security thread 20 is included in the paper web by guiding the thread through a speed-promoting mechanism 24 and through an optical sensor 32b, and then between the roll 50 and the surface of the paper web exiting the cylinder paper machine 36a. In this case, the security thread 20 may be partially or completely located above the watermark (s) on the surface of the paper web. The paper web 40 with the security thread 20 applied to the surface and watermark (s) is then sent between the roller 44 and the surface of the second paper web 42 emerging from the cylinder paper machine 36b, where two paper webs are pressed against each other. The second paper web 42 is uniform and serves to mask irregularities in the formation of paper on the back or bottom surface of the first paper web 40, which may be caused by the presence of the yarn 20.

As indicated above, the forming cylinder 48 may have protruding and / or recessed zones on its surface, which may completely or partially overlap the zones in contact with the thread 20 during manufacture.

As in previous embodiments, machine alignment between the security thread 20, the watermark (s) and the paper web 40 is achieved using a speed-adjustable security thread advance mechanism 24, optical sensors 32a, 32b for tracking registration marks on the forming cylinder 48 and on the security thread 20 and the coding disk 34 for monitoring the speed of the paper formed on the cylinder paper machine 36a.

After exiting the calender section of any of the aforementioned paper machines, the fiber sheet material of the invention can be wound for storage or directly inserted into another machine (e.g., printing press) for further processing.

In a second typical embodiment, the security paper according to the invention is a multilayer paper, including:

a first paper layer having a reduced grammage (for example, from about 10 to about 50 g / m ² ) and comprising one or more watermarks, each surface of the first paper layer showing the top or face of one or more watermarks or him (s) bottom or back; and

a second paper layer having a reduced grammage (for example, from about 10 to about 50 g / m ² ) and optionally one or more through windows, the second paper layer covering either the surface of the first paper layer showing the upper or front part of one or more a watermark, or a surface showing the bottom or back of one or more watermarks.

In one such embodiment, the second paper layer is a window, with one or more through windows in the second paper layer coinciding with one or more watermarks. Thanks to this typical embodiment, the use of two paper layers and, optionally, one or more overlying through windows, allows greater contrast between one or more watermarks and the background.

In a third typical embodiment, one or more security elements in the form of one or more coloring agents are contained within the first and / or second portions of one or more watermarks. One or more coloring agents include both dyes and pigments (for example, ultrafine pigments). As noted above, in this embodiment, the security sheet or document does not include one or more film-like or foil-like security elements. The resulting watermarks have a tonality (i.e., color scheme or gradation of tones) in a color or shade different from the main portion of the material surrounding the watermarks, which serves to enhance their perception and resistance to imitation.

Watermarks traditionally have the same color as the paper substrate on / in which they are made. These signs are formed by a localized change in the thickness of the paper, which changes the opacity of the paper, making the watermark visible in transmitted light or in reflected light against a dark background.

A watermark according to the prior art or a standard watermark is shown on one colored paper substrate in FIG. 7. In this case, there is only a slight contrast between the light and dark areas of the watermark, which makes the watermark more difficult to distinguish. For comparison, FIG. 7 also shows that the reinforced watermark according to the present invention, which includes one or more coloring agents in the form of one or more visible (color) pigments (i.e., blue), has an improved quality, which consists in a significantly greater contrast between light and dark areas in the watermark. Thus, it is easier to attract attention from the general public to a watermark according to the invention, which increases the effectiveness of this security feature.

Another typical embodiment of the present invention is shown in FIG. 8. In this case, the watermark according to the invention contains a second level security feature in the form of a substance excited in the UV region in addition to one or more coloring agents. The watermark according to the invention not only shows a noticeable contrast between the light and dark areas in the transmitted light, but because it also contains a substance excited by UV radiation, it also demonstrates a tonality of the UV reaction, which is difficult to reproduce, which makes this embodiment of the watermark is even more resistant to fakes.

As shown in FIG. 9, in a typical embodiment, in which the security sheet or document is a paper security document, a method of manufacturing a security document according to the invention includes producing a continuous roll of watermarked paper 52 on a paper machine 54 (FIG. 9a), wherein the watermarks or sections 56c watermarks are repeated along the length of the paper (FIG. 9b), each of which has areas of a smaller grammage (i.e., first sections) and areas of a larger grammage (i.e., second sections) to provide brighter and more GOVERNMENTAL regions 56 in the areas of the watermark, the method comprising:

applying a color solution 58, including coloring matter, to a plurality of watermark sections 56 on one side of a continuous roll of paper while applying vacuum on the opposite side of the paper to draw the applied color solution into the paper,

moreover, areas 56 of a larger grammar of a watermark contain more coloring substances, and areas of a smaller grammage contain less coloring substances, thereby providing tonality of sections of the watermark with a color or shade different from the color or shade of the main sections of paper surrounding a plurality of sections of the watermark, repeated by lenght.

As indicated previously, watermarks are formed by well-known methods, for example, on a round-mesh paper machine or a long-mesh paper machine (using a leveler). For the manufacture of paper, a number of types of fibers are used, including synthetic or natural fibers or a mixture thereof.

A “color solution” toning a watermark according to the present invention includes one or more of the aforementioned coloring agents, including both dyes and pigments (for example, ultrafine pigments).

After the watermarks are formed on the paper machine 54, local application of the color solution 58 is performed on the watermarked areas 56 of the paper while the paper is still wet, and on the forming net and before any compression drying is performed. The color solution is applied to a continuous roll of watermarked paper 52 using a periodic low-volume spray using nozzles 60 arranged in line with the watermarked areas of the paper. The color solution is introduced into the paper web using one or more vacuum frames 62. Although in FIG. 9b shows two vacuum frames, in the practical implementation of the method according to the invention, one or more vacuum frames can be used.

In a fourth exemplary embodiment, which may be defined as a "translucent" watermark, one or more polymer or resin materials are contained within the first (s) section (s) and, optionally, the second (s) section (s) of one or more watermarks. As noted above, the security sheet or document in this typical embodiment does not include one or more film-like or foil-like security elements. The first and / or second sections in this embodiment may also contain one or more security features selected from the group that includes areas with increased fiber density in the form of recognizable or distinguishable signs, one or more substances that impart color, and one or several security features of the second level, which are machine detectable or machine readable, as described above.

The translucent embodiment of the watermark of the present invention provides a security feature that is easily recognizable by the general public for first-level authentication. Watermarks according to the invention, which may be a "paper" sign, allow authentication due to their transmission properties. The inclusion of such a translucent or transparent part in a security document (for example, a banknote) cannot be reproduced by scanning, visual analysis and further use of digital copy technologies.

In a typical embodiment, the translucent (s) watermark (s) according to the invention are obtained in the framework of paper production during the formation of a wet lime. For example, a paper web is produced in a continuous manner on a long-mesh paper machine. The pulp is deposited from the headbox onto a continuously moving wire mesh. Then water from the pulp drains through the wire mesh, leaving a moist, dehydrated fiber mat.

The translucent (s) watermark (s) according to the invention is first formed by removing the paper pulp from selected sections of the fiber mat, resulting in a decrease in fiber density (see FIG. 10). This can be carried out using traditional methods, for example, using a leveler (or cylinder bath). Selected areas with a lower fiber density (i.e., first portions) have less opacity compared to other areas of the watermark (s) (i.e., second portions) and other areas of the fiber mat (i.e. ., the main sheet), although they are not transparent. Then, the first and, optionally, second portions of the watermark (s) are treated with one or more polymer or resin materials selected for a final refractive index close to that of the cellulose (e.g., UV curable, electron beam curable or thermally curable polymer or resin material).

The first and second sections are treated with one or more polymer or resin materials on a paper machine in an autonomous process for processing roll material, such as rewinding, in a specially provided autonomous process for processing roll material before cutting a sheet, or on separate sheets.

One or more polymeric or resinous materials that saturate the paper in the first and optionally second portions of the watermark (s) (displacing air between the fibers) are optionally applied in the form of a pattern to these portions, and they can also be exposed curing by irradiation, thermal / catalytic or oxidizing agents.

As best shown in FIGURES 11a, b, it is now possible to transmit visible light through the resulting translucent (e) or transparent (e) watermark (s). As a result, the printed material observed under the translucent (s) watermark (s) (s) is easy to read.

The selection of polymer (s) or resin (s) material (s) with appropriate characteristics also allows embossing, application within translucent or transparent areas, for example, before printing or during the intaglio printing process.

The translucent (s) watermark (s) according to the invention may also include one or more features within their perimeter selected from the group that includes areas with increased fiber density in the form of recognizable or distinguishable signs, one or more substances, which give color, and one or more second level security features that are machine detectable or machine readable, as described above.

These signs, for example, in the form of fibers or confetti, can be added by accidental addition to the pulp or selectively in the flow mode placed in the position of the translucent protective element. In an additional or alternative embodiment, such inclusions can be concentrated in specific transversely directed areas of the paper.

In a fifth exemplary embodiment, the security sheet or document of the invention is a single-layer paper including:

a paper layer comprising one or more watermarks; and

one or more transparent or translucent areas in the paper layer surrounding each of one or more watermarks, which thus frame, and therefore enhance the visual perception of, the watermark (s).

Such frame regions can be formed in the watermarked paper layer by treating the areas surrounding each watermark with one or more transparency-imparting polymeric or resin materials, such as UV curable, electron beam curable or thermally curable polymeric or resin material.

These frame regions are treated with transparency material (s) on a paper machine in an autonomous roll material processing process, such as rewinding, in a specially provided autonomous roll material processing process before cutting a sheet, or on separate sheets.

The transparency material (s) saturates the paper (s) in the application, displacing air between the fibers. This (these) material (s) may (may) be curable (s) or non-curable (s). The treated areas of the watermarked paper layer allow conducting visible light, which, thus, framing, and thus enhancing the visual perception of the watermark (s).

Although various embodiments of the present invention have been described above, it should be understood that they have been presented by way of example only and do not limit the scope of the invention. Thus, the width and scope of the present invention should not be limited to any typical embodiments.

Claims (17)

1. A protected sheet or document having one or more reinforced watermarks or watermark designs, which includes: fiber sheet material comprising one or more watermarks or watermark designs, each watermark design having one or more first sections with a reduced fiber density relative to the surrounding sections of the fiber sheet material, and one or more second sections with a similar or increased fiber density relative to surrounding sections of the sheet material, and each watermark design has an upper or front part and a lower or rear part; and means for enhancing one or more watermarks or watermark designs, making them visually enhanced, machine-detectable or readable, or both of these properties, the aforementioned means include: one or more film-like or foil-like protective elements, at least partially covering the front or back of one or more designs of the watermark, and one or more film-like or foil-like protective elements are provided in the form of a tape, strip, thread or flap; and wherein one or more film-like or foil-like security elements is one or more micro-optical film materials, each of which includes a plurality of microlenses and a plurality of pictograms configured in such a way that when a plurality of pictograms is observed through the plurality of microlenses, one or more synthetically projected enlarged optical images, each of one or more micro-optical film materials showing color images on a transparent or lightly colored background, and each of them shows a color image on a translucent or substantially opaque background of a different color. 2. A protected sheet or document according to claim 1, characterized in that one or more of the first sections with a reduced fiber density of one or more watermark designs has a thickness of 10 to 15 microns and a total area within each watermark design of from about 5 to approximately 75 percent of the total watermark design area, with the total area of each watermark design within a banknote of approximately 10,000 square millimeters being from about 5 to about 25%. 3. A protected sheet or document according to claim 1, characterized in that one or more synthetically enlarged optical images are coordinated or connected to one or more watermark designs. 4. A security sheet or document according to claim 1, characterized in that one or more micro-optical film materials is performed using only infrared transparent materials, wherein the security sheet or document exhibits enhanced IR brightness, in particular when measured in transmitted light. 5. A protected sheet or document according to claim 1, characterized in that one or more micro-optical film materials is provided in the form of a patch or thread that completely or partially covers one or more watermarks or watermark designs, one or more watermark designs contain one or more polymeric or resin materials in any or both of one or more of the first sections and one or more second sections, and one or more polymer or resin materials have refractive index or combined refractive index, essentially similar to the cellulose index. 6. A protected sheet or document according to claim 5, characterized in that any or both of the one or more first sections and one or more second sections of one or more watermark designs also include one or more features selected from the group to which areas with a high density of fibers in the form of recognizable or distinguishable signs, one or more substances that add color, and one or more second level security features that are machine detectable or machine readable ju, in the form of reacting to ultraviolet or infrared rays, luminescent, thermochromic, photochromic, electrochromic, metal or magnetic protective fibers, markers, confetti, dyes, pigments. 7. A protected sheet or document according to claim 1, characterized in that it is a multilayer paper, including: a first paper layer having a reduced grammage of from about 10 to about 50 grams per square meter and including one or more watermarks or watermark designs, each surface of the first paper layer showing the upper, or front, part of one or more watermark designs or its (their) lower, or back, part; and means for enhancing one or more watermarks or watermark designs in the form of a second paper layer having a reduced grammage from about 10 to about 50 grams per square meter and optionally one or more through windows, the second paper layer covering either the surface of the first paper layer showing the upper, or front, part of one or more watermark designs, or a surface showing the bottom, or back, part of one or more watermark designs. 8. A protected sheet or document according to claim 1, characterized in that the means for enhancing one or more watermarks or watermark designs include one or more coloring substances contained in any or both of one or more of the first sections and one or more second sections one or more watermark designs, wherein one or more watermark designs have tonality in a color or shade different from the main portion of the material that surrounds one or more watermark designs sign when observed in transmitted light or when observed in reflected light on a dark background. 9. A protected sheet or document according to claim 8, characterized in that any or both of one or more of the first sections and one or more second sections of one or more designs of the watermark also include one or more features selected from the group to which areas with increased fiber density in the form of recognizable or distinguishable signs, and one or more second level security features that are machine detectable or machine readable, in the form of reacting to ultraviolet or frakrasnye rays, fluorescent, thermochromic, photochromic, electrochromic, magnetic or metallic protective fibers, markers, confetti, dyes, pigments. 10. A protected sheet or document according to claim 1, characterized in that the means for enhancing one or more watermarks or watermark designs include one or more polymer or resin materials contained in either or both of one or more of the first sections and one or more second sections of one or more watermark designs. 11. A protected sheet or document according to claim 10, characterized in that any or both of one or more first sections and one or more second sections of one or more watermark designs also include one or more features selected from the group to which areas with increased fiber density in the form of recognizable or distinguishable signs, one or more substances that impart color, and one or more second level security features that can be detected or read by machine in the form of reacting to ultraviolet or infrared rays, luminescent, thermochromic, photochromic, electrochromic, metal or magnetic protective fibers, markers, confetti, dyes, pigments. 12. A protected sheet or document according to claim 1, characterized in that the means for enhancing one or more watermarks or watermark designs include one or more transparent or translucent areas surrounding each of one or more watermarks.

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