Abstract: The printed product comprises a carrier (1) provided with a relief on the surface thereof in the form of a plurality of grooves and a main visible image transmitted by an ordered screen, wherein said relief and the screen structure of the visible image are embodied in such a way that at least one additional image becomes manifest on the main image background when a lighting or viewing angle is modified. According to the invention, the angle and period (d) of the groove tracing is equal to the angle and lineature of the main image screen, and geometrical distortions whose value corresponds to the value of tonal gradations of the additional image are introduced into the relief and/or the main image screen structure without breaking the continuity of the pattern lines forming said screen and relief, whereby a nonuniform system of cross-points of the grooves with the screen pattern lines (8) forming said additional image is created.

Abstract: The invention relates to a security element comprising a carrier substrate comprising a transparent or translucent area carrying at least one digitised mark made of at least one set of dots appearing as a three dimensional mark when viewed in transmitted light. The invention relates to a security support or document or article comprising the said security element and to the method of identification and/or authentication of this security support or document or article.

Abstract: A forgery-proof value document, in particular a postage stamp, is examined for its authenticity. The value document contains a two-dimensional area with a security element in the form of a two-dimensional structure. The two-dimensional area is provided with, for example printed with, at least one first and at least one other substance. When illuminated with light that is visible to the human eye, the two substances have the same hue and different hues when illuminated with infrared light. The security element is placed on the value document by use the first substance, the remaining part of the area by use of the at least one other substance. When illuminated with visible light the entire two-dimensional area appears in the same hue. When illuminated with infrared light the security element is optically distinguished from the remaining area.

Abstract: Apparatus and related methods align magnetic flakes in a carrier, such as an ink vehicle or a paint vehicle to create optically variable images in a high-speed, linear printing operation. Images can provide security features on high-value documents, such as bank notes. Magnetic flakes in the ink are aligned using magnets in a linear printing operation. Selected orientation of the magnetic pigment flakes can achieve a variety of illusive optical effects that are useful for decorative or security applications.

Abstract: A method for implementing a secure printing campaign to thwart counterfeiting is provided. The method includes the steps of selecting a first secure print technology and a second secure print technology that is distinct from the first secure print technology, selecting a first secure print variable for the first secure print technology and a second secure print variable for the second secure print technology, and establishing a first plurality of discrete values for the first secure print variable and a second plurality of discrete values for the second secure print variable.

Abstract: The present invention is directed to a method and system for printing documents with a security image. The security image is formed of dots of a particular size and arranged in a pattern. The size and pattern are selected such that when the printed document is copied on a standard printer the security image is faded or invisible and therefore the resulting copy is clearly not an original document.

Abstract: An identification document which includes card specific information printed on the card in a first location at a relatively large scale which permits the information to be read without magnification and duplicates the card specific information at a second location on the card at a significantly smaller scale which requires magnification to clearly read the small scale information. The micro-printing of small scale card specific information, such as a person's date of birth on a driver's license, at a second location on the identification card allows the micro-printed text to be compared to the large scale text to determine if the large scale text has been altered.

Abstract: The invention teaches a paper substrate having a laser treated area which has benefits for anti copy, copy deterrence and/or copy detection applications. The laser treatment may be in the form of a dense array of a plurality of microperforations which may or may not be visible to the naked eye or in form of fine graphics on the paper surface incorporated via partial ablations. The laser treated area serves as an authenticated field. In one aspect, the authentication field when copied on reprographic equipment reproduces as a field of dark separated dots. The authentication field optionally can take the form of various shapes including alphanumeric characters or other patterns. In an alternate aspect the laser treated area is an area of laser-formed partial ablations creating a synthetic watermark.

Abstract: A security document and a method of making and authenticating the document in which the document contains a security feature of an image/background pattern printed in one subtractive color on the document and at least one other but different image/background pattern printed in another subtractive color superimposed directly over the one image/background pattern.

Abstract: A multiple-layered watermark is generated to be placed on document, to protect against counterfeiting and forgery. Hidden information embedded into each of the watermark's layers is only detectable by using a corresponding decoder. Because of the multiple-layered structure, it is difficult to reverse engineer the optical watermark. The generalized watermark structure significantly increases the “key space” of the decoder.

Abstract: A printed article is disclosed having a light transmissive substrate having a reverse printed region on a surface thereof in the form of a plurality of very closely spaced printed lines or regions. The printed regions and spaces therebetween are subsequently flood coated with special effect ink such as optically variable ink wherein the ink particle size is on average greater than the gap between reverse printed regions. The image is viewed from the non-printed side of the substrate and very fine lines of the special effect flood coated special effect ink appear as very clear sharp lines having a fine resolution. This eliminates the typical jagged edges that would otherwise be seen if the inked region was not present. This effect is due to the first printed inked regions or lines forming a mask through which the flood coated ink is seen.

Abstract: An authenticity discriminable printed matter in which a latent image cannot be visually identified under ordinary visible light but appears upon being irradiated with UV rays. A basic image is formed on a base material. The basic image is made of a latent image portion and latent image peripheral portion. The latent image portion and latent image peripheral portion cannot be visually discriminated, and each of them is formed from a set of dots continuously laid out at a predetermined period. The resolution of the dots of the latent image portion is different from that of the dots of the latent image peripheral portion. The latent image portion and latent image peripheral portion have the same percent dot area per unit area and different dot peripheral lengths (contour lengths) per unit area. The latent image portion and latent image peripheral portion are printed by color fluorescent ink, thus obtaining printed matter.

Abstract: A digital imaging kiosk, comprising an imaging device adapted to electronically capture an image of an object, a display device adapted to display at least one of a captured image, a user interface adapted to display information to a user and to receive information from a user, a printing device adapted to print a manipulated or non-manipulated image on one or more sides of one or more substrates, a substrate handling device adapted to position a substrate in proximity to the printing device such that the printing device can print to the one or more substrates, a control unit in communication with the information suite, wherein the kiosk is adapted so that the printing device prints the image captured by the image capturing device on a first side of a set number of substrates having a preprinted and unique image on a second side of the set number of substrates.

Abstract: A printing control apparatus is provided which can produce an appropriate copy-forgery-inhibited pattern image by adding a monochrome copy-forgery-inhibited pattern even if monochrome mode printing is performed in the condition in which a color copy-forgery-inhibited pattern is set. When the monochrome mode printing is performed in the condition in which the color copy-forgery-inhibited pattern is set, and if the copy-forgery-inhibited pattern color is output with its color unchanged, the color is not converted into 100% black. Considering this, when a forced monochrome mode is selected and a user's setting for the copy-forgery-inhibited pattern is color, the user is notified to change a printing mode. Otherwise, the user is notified that the setting of the printing mode and the setting of the copy-forgery-inhibited pattern are conflicting.

Abstract: In a substrate having a graphic and a method for applying the graphic thereto, a non-phosphorescent material is applied to the substrate to define a non-phosphorescent region of the graphic and a phosphorescent material is applied to the substrate to define a phosphorescent region of the graphic. At least a portion of the non-phosphorescent region and at least a portion of the phosphorescent region are in overlapping relationship with each other so as to define an overlapping region of the graphic. When the overlapping region is exposed to light sufficient to cause phosphorescence of the phosphorescent region the at least a portion of the phosphorescent region phosphoresces to render the overlapping region visible in the absence of light. In another embodiment, the graphic has a non-photoluminescent region in overlapping relationship with a photoluminescent region.

Abstract: A printing control apparatus is provided which can produce an appropriate copy-forgery-inhibited pattern image by adding a monochrome copy-forgery-inhibited pattern even if monochrome mode printing is performed in the condition in which a color copy-forgery-inhibited pattern is set. When the monochrome mode printing is performed in the condition in which the color copy-forgery-inhibited pattern is set, and if the copy-forgery-inhibited pattern color is output with its color unchanged, the color is not converted into 100% black. Considering this, when a forced monochrome mode is selected, even if the user's setting for the copy-forgery-inhibited pattern is color, the color is changed to monochrome (black) before output.

Abstract: This invention discloses new methods, security devices and apparatuses for authenticating documents and valuable articles which may be applied to any support, including transparent synthetic materials and traditional opaque materials such as paper. The invention relates to moire intensity profiles which occur in the superposition of specially designed random structures. By using specially designed random basic screen and random master screen, where at least the basic screen is comprised in the document, a moire intensity profile of a chosen shape becomes visible in their superposition, thereby allowing the authentication of the document. An important advantage of the present invention is that it can be incorporated into the standard document printing process, so that it offers high security at the same cost as standard state of the art document production.

Abstract: Holographic and diffractive security devices and documents carrying security devices as well as system, apparatus, and method for making and using security devices. Security devices provide at least one type of security feature in form of secret, hidden, or covert security feature, not visible to a normal unaided human eye. Covert security features may be any graphic or symbolic representation. One or multiple security features may be provided on any single security device in any combination. Covert feature is revealed either when a decoder device is used with the security device, or when the security device is oriented and viewed in predetermined manner. Embodiments may provide a second overt or non-covert security device in the form of a diffractive or holographic image or graphic that is visible to the unaided eye without use of any decoder or special viewing conditions.

Abstract: This invention discloses new methods, security devices and apparatuses for authenticating documents and valuable articles which may be applied to any support, including transparent synthetic materials and traditional opaque materials such as paper. The invention relates to moire intensity profiles which occur in the superposition of periodic or aperiodic geometrically transformed structures. By using a specially designed basic screen and master screen, where at least the basic screen is comprised in the document, a moire intensity profile of a chosen shape becomes visible in their superposition, thereby allowing the authentication of the document. If a microlens structure is used as a master screen, the document comprising the basic screen may be printed on an opaque reflective support, thereby enabling the visualization of the moire intensity profile by reflection.

Abstract: A microparticle taggant having two or more distinguishable marker layers corresponding to a predetermined numeric code. The plurality of particles comprises a plurality of microparticle sets of at least one microparticle, each microparticle set is characterized by a specific marker layer combination different from each other microparticle set, and the combination of microparticle sets employed in said taggant collectively forms the numeric code. Each specific marker layer combination may employ two or more layers. The microparticle sets employed in the taggant may include at least one datum marker layer coded to include place information and at least two value marker layers coded to specify a value within the place, the datum marker layer(s) being readily distinguishable from the value marker layers and functioning to identify an orientation of the value marker layers.

Abstract: Additional data useful for the management of copies of a document for an image forming apparatus is embedded in a hard copy of the document. The additional data is embedded in an image of a document as discrete dots arranged in a prescribed format. Preferably, the size of each of said discrete dots is such as not to be recognized easily with the naked eye. The image data for embedding the additional data can be obtained by reading a document, or by receiving data sent from a computer. Additional data embedded in a hard copy can be extracted from the image data on the hard copy. Further, the production of a copy according to the image data, can be controlled according to the extracted additional data. Additional data is generated for each copy according to the extracted additional data for embedding it in a hard copy to identify each copy.

Abstract: A discrete micro particle having a micro image, a method of making discrete micro particles and use in authentication of products. The micro images are printed on a photo sensitive layer on a media and the media is ground into small discrete particles on which the micro images can be viewed for verification of the authenticity of a product on which the micro particles have been placed.

Abstract: An apparatus for authenticating an object on the basis of incorporating onto the object at least one security feature known as a microdot which includes plural unique microscopic patterned markers each of which include indicia and the method of making such microdots.

Abstract: A counterfeit-resistant document comprises a substrate and a nano-pattern of nano-structures disposed on the substrate, wherein the nano-pattern is configured for forming a latent message (e.g., a warning or alert message) that appears on a copy of the document. The nano-pattern forms one of a foreground and a background of the latent message; and another pattern, e.g., a conventional pattern or another nano-pattern, forms the other of the foreground and background of the latent message. The nano-pattern and the other pattern are configured, such that the foreground and background exhibit substantially similar visual densities on an original of the document, and exhibit substantially different visual densities on the copied document. This can be accomplished by forming the nano-pattern with nano-structures (e.g.

Abstract: Quantum dots are used as fluorescent taggants in security inks, papers, plastics, explosives, or any other item or substance in which it is desired to provide a distinct signature or marking. Quantum dots of specific sizes, compositions and structures may be used to produce specific fluorescence, mixtures of quantum dots can be used to produce random patterns of spectrally varying fluorescence, and particular quantum dot structures can be used to provide desirable physical and optical properties. The quantum dots may be read with an optical reader, which may be combined with readers using other technologies.

Abstract: A security document, banknote, bond, travellers check, passport or token, including a substrate (1), said substrate having a device including a first macro-embossing (2, 3) of the substrate having a predetermined feature, and a second micro-embossing of smaller dimensions formed in or on said predetermined feature of said embossing. The first embossing being formed to hide and reveal said second embossing at predetermined viewing angles &agr;, &bgr;. The macro-embossing may comprise lines having a height of about 20 microns and a spacing of 80 microns, and the micro-embossing in the form of lines or dots (4) to a height of about 2 to 5 microns. The lines have a predetermined height (H) and a predetermined spacing (S) such that the ratio S:H is typically from about 6:1 to 2:1.

Abstract: A microparticle taggant having two or more distinguishable marker layers corresponding to a predetermined numeric code. The plurality of particles comprises a plurality of microparticle sets of at least one microparticle, each microparticle set is characterized by a specific marker layer combination different from each other microparticle set, and the combination of microparticle sets employed in said taggant collectively forms the numeric code. Each specific marker layer combination may employ two or more layers. The microparticle sets employed in the taggant may include at least one datum marker layer coded to include place information and at least two value marker layers coded to specify a value within the place, the datum marker layer(s) being readily distinguishable from the value marker layers and functioning to identify an orientation of the value marker layers.

Abstract: This invention comprises a transferable support comprising a substantially flat sheet having on a surface thereof encoded data in the form of dot code or two-dimensional bar code wherein the data is capable of being read by a sensor. The invention also comprises object having affixed to a surface thereof a support comprising a substantially flat sheet having on a surface thereof encoded data in the form of dot code or two-dimensional bar code wherein the data is capable of being read by an sensor.

Abstract: A system for producing a white-light interference hologram includes a camera adapted for recording a first and a second bitmap image of a scene from separate vantage points, and the separation distance of the vantage points, a computing engine adapted to compute three-dimensional x, y, and z characteristics of an interference hologram topology for the scene from the bitmap image and separation data, wherein x and y are two dimensional locations of bits in a bitmap of the topology and z is a depth dimension for each x,y bit, and a printer adapted to print in color the x,y bitmap, and to create the depth dimension z at each x,y bit location, providing thereby a three-dimensional interference hologram topology for the scene. In a preferred embodiment the depth dimension is created by electrophoresis, using a medium having an electrophoretic gel layer, with the ink applied to the gel in a bit-mapped pattern being ionic in nature, and capable of being migrated in the gel layer by electrophoresis.

Abstract: Proposed is a value-bearing document in which the carrier is provided with a window-like opening which is closed by a cover foil which is transparent at least in a region-wise manner, wherein particularly in the region of the window-like opening, the cover foil can be provided with additional security features, for example diffraction structures.

Abstract: Individual glyph frames for providing simple data blocks that may be read individually. A frame is usually on the order of ⅙th of an inch in size and can be used as a pointer to anywhere on the page or can contain a small piece of data such as the page or form number.

Abstract: A diffractive anti-counterfeiting tag structure with capabilities of naked-eye inspection and machine inspection and its method of manufacture. The anti-counterfeiting tag structure has a naked-eye inspection component and a machine inspection non-grating diffractive component. The naked-eye inspection component and the non-grating diffractive component are formed on separate mold-boards and then joined together to form a mold-board using a board-joining technique. Alternatively, a plurality of naked-eye inspection blocks and a plurality of non-grating diffractive blocks are randomly mixed together to form a pixel-like diffractive anti-counterfeiting tag.

Abstract: A counterfeit-resistant document comprises a contrasting layer and a dynamic camouflaging layer. The contrasting layer is highly contrastive and includes a latent message that can be reproduced over a broad range of copy device control settings. The dynamic camouflaging layer is applied over the contrasting layer to suppress the latent message. The visual density of the dynamic camouflaging layer, which comprises a camouflage pattern that is printed in thermochromic ink, inversely varies with temperature. In this manner, the dynamic camouflaging layer is inactivated at room temperatures so that the latent message is suppressed on the original document, and activated at scanning temperatures so that the latent message is exhibited on a reproduction of the original document.

Abstract: A data carrier with at least one halftone images 10 represented by structural elements 12, whereby a predetermined symmetrical widening of structural elements 12 represents a corresponding gray level of halftone image 10. Image 10 has predetermined areas 14, 16 and 22 each having a predetermined number or screen frequency of structural elements 12, the screen frequency of structural elements 12 per unit area of area 14, 16 and 22 being different between at least two areas 14, 16 and 22 and/or structural elements 12 being offset from each other in at least two areas 14, 16 and 22. A data carrier with such a halftone image 10 acquires a moiré pattern in at least predetermined areas of halftone image 10 when copied, so that a copy of the data carrier is recognizable immediately and with the naked eye (FIG. 1).

Abstract: Quantum dots are used as fluorescent taggants in security inks, papers, plastics, explosives, or any other item or substance in which it is desired to provide a distinct signature or marking. Quantum dots of specific sizes, compositions and structures may be used to produce specific fluorescence, mixtures of quantum dots can be used to produce random patterns of spectrally varying fluorescence, and particular quantum dot structures can be used to provide desirable physical and optical properties. The quantum dots may be read with an optical reader, which may be combined with readers using other technologies.

Abstract: A security stock material for use in lottery tickets or other instruments where prevention of the viewing of indicia on the lottery ticket is achieved despite tampering to make the stock material translucent by chemical or other means. A method of making the stock material by combining natural brown kraft linerboard with bleached fibers on one side and a black ink or black coating on the other side is also disclosed.

Abstract: A tape data carrier for protecting articles and documents from counterfeiting and copying is formed by a polymer structure including at least one polymer layer of which at least one layer has at least one of through-perforations and pits. These through-perforations and pits are preferably between 0.001 &mgr;m and 20 &mgr;m in size and can be filled with different materials. The data carriers can carry concealed and visible macro-and micro- images created by heavy-ion bombardment of the polymer film, subsequent exposure of the bombarded film to ultraviolet radiation, and etching of the polymer film in a solvent. A device for manufacturing a data carrier of this type includes the following elements configured in series: a heavy ion source; a heavy ion beam-formation system; an ion guide; a three-dimensional amplitude modulation unit; and a target which is destined to become the data carrier.

Abstract: A surface pattern (1) is composed of elements (2 to 5) which are arranged in a mosaic-like fashion and of which at least one pattern is formed from a background element (4) and a pixel (2) with microscopically fine relief structures diffracting visible light. The surface elements (3) and the element portions (5) either contain the microscopically fine relief structures diffracting visible light or they comprise reflecting or scattering surfaces. Arranged in the pixel (2) is a first diffraction grating B1 and arranged in the background element (4) is a second diffraction grating B2, wherein the first diffraction grating B1 and the second diffraction grating B2 are a superimposition of at least two different, microscopically fine relief structures F1 and F2 diffracting visible light. The first diffraction grating B1 and the second diffraction grating B2 differ only by virtue of a relative phase shift &Dgr;&phgr; between the relief structure F1 and the relief structure F2.

Abstract: A security document production scheme is presented for the creation of a security document including a prismatic multi-color security image. In accordance with one embodiment of the present invention, a security document is provided comprising a security image defined on a face of the document. The security image is defined along first and second dimensions by the superposition of a primary security image portion and a secondary security image portion. The primary security image portion is defined by security image elements of a first color. The secondary security image portion is defined by security image elements of a second color. The primary security image portion is arranged to include first, second, and third types of security image segments. The secondary security image portion is arranged to include first, second, and third types of security image segments.

Abstract: A document has a substrate with a first side. The first side has a first area within which the substrate is a first color. The document also has a plurality of marks on the substrate within a second area. The second area is smaller than the first area and is within the first area. Each mark is a different color from the first color. The density and size of the marks is such that at a distance of about twenty inches, the first area appears to the human eye to have a shaded area corresponding to the second area, as well as an unshaded area corresponding to a portion of the first area not occupied by the second area. At a distance of about eight inches, the second area appears to the human eye to have a plurality of marks.

Abstract: A protected/security document is provided that foils counterfeiting even if a laser photocopy machine (such as a Canon 500 color copier) is utilized. The document has at least three discrete half-tone printed bands disposed on its surface, provided by dots or lines. Each printed band has a different screen density and within each bands the dots or lines comprise a warning word or symbol (e.g. “Void”), or a background. The dots or lines of either the “Void” or background drop out when photocopied, while the dots or lines of the other do not. The dots or lines that do not drop out may be dimensioned so that there are about 24-34 per centimeter, while for those that do drop out there are about 52-64 per centimeter. The bands are typically arranged either linearly or in concentric circles, and interband areas having density gradually transitioning between the densities of adjacent bands are provided.

Abstract: A latent image structure of a highly secure nature in which two latent image are superimposed. Each of the superimposed latent images is viewable from a different line of sight. Relief elements define, for each latent image, portions of respective linear relief structures providing an image and a background which cooperate to generate the latent image. Relief elements are only provided at locations where the linear relief structures of the first and second latent images intersect. The resultant latent image structure, when viewed normally, has the advantage of a relatively flat appearance, making it difficult to discern the presence either of the superimposed latent images.

Abstract: A security document production scheme is presented for the creation of a security document including a prismatic multi-color security image. In accordance with one embodiment of the present invention, a security document is provided comprising a security image defined on a face of the document. The security image is defined along first and second dimensions by the superposition of a primary security image portion and a secondary security image portion. The primary security image portion is defined by security image elements of a first color. The secondary security image portion is defined by security image elements of a second color. The primary security image portion is arranged to include first, second, and third types of security image segments. The secondary security image portion is arranged to include first, second, and third types of security image segments.

Abstract: The present invention relates to a new method and apparatus for authenticating documents such as banknotes, trust papers, securities, identification cards, passports, etc. The documents may be printed on any support, including transparent synthetic materials and traditional opaque materials such as paper. This invention is based on moire patterns occuring between superposed dot-screens. By using specially designed basic screen and master screen, where at least the basic screen is comprised in the document, a moire intensity profile of a chosen shape becomes visible in their superposition, thereby allowing the authentication of the document. If instead of the master screen a microlens array is used for the authentication purpose, the document comprising the basic screen may be printed on an opaque reflective support, thereby enabling the visualization of the moire intensity profile by reflection.

Abstract: A method for permanently marking a photoreceptor surface includes the steps of irradiating a surface of a photoreceptor with an irradiation source to permanently mark the photoreceptor, and ablating material from the photoreceptor to at least one controlled depth in the photoreceptor with the irradiation source.

Abstract: A security document is provided including a unique combination of covert triggers, overt triggers, and overt secure document indicators arranged to enhance the security of the document at issue. In accordance with one embodiment of the present invention, a security document is provided including a security image and a covert trigger printed on a face of the document. The security image is defined by a collection of security image elements. The security image defines at least one document authentication scheme. The document authentication scheme is arranged to provide an indication of document authenticity. The covert trigger is defined by a collection of trigger elements. The trigger elements are arranged to resemble the security image elements so the covert trigger is not readily apparent on the face of the document. In accordance with another embodiment of the present invention, a method of authenticating a security document is provided.

Abstract: A security document production scheme is presented for the creation of a security document including a prismatic multi-color security image. In accordance with one embodiment of the present invention, a security document is provided comprising a security image defined on a face of the document. The security image is defined along first and second dimensions by the superposition of a primary security image portion and a secondary security image portion. The primary security image portion is defined by security image elements of a first color. The secondary security image portion is defined by security image elements of a second color. The primary security image portion is arranged to include first, second, and third types of security image segments. The secondary security image portion is arranged to include first, second, and third types of security image segments.

Abstract: An anti-copy layer or film for documents that is substantially transparent to the legitimate user, comprising a multiplicity of small fragments of spectral material embedded within an optically clear coating, wherein multi-angular illumination of the fragments by a copy apparatus generates sufficient amounts of visual noise in a copy as to prevent true-copy replication of the documents.

Abstract: A paper substrate is laminated with a metalized layer forming a mirrored surface. A partially transparent black diffraction grating is applied by stochastic screening to the mirrored surface. The diffraction grating forms a random pattern from selected geometric shapes. Information, such as alphanumeric indicia or graphics, is printed on the stochastic screen to thus form a reflective diffraction device which is printable in a conventional manner while inhibiting reproduction of the printed information by conventional techniques, including black and white and color photo-reproduction and facsimile machines. The partially transparent black stochastic screen forms a diffraction grating on the metalized layer so that when illuminated from the light source of either a specular or diffuse illumination-type photocopier, random interference patterns of light occur at the interface of the metalized surface and the stochastic screen.

Abstract: A security document is provided comprising: a security image area on the face of the document and a printed security image within the security image area. At least a portion of the security image area is divided into a plurality of image element cells, such that the image element cells define an array of image element cells across the security image area. Each of the image element cells is divided into a plurality of pixels, such that each image element cell defines a cell pixel array. At least a portion of the security image area is divided into a plurality of complementary image element cells, such that the complementary image element cells define an array of complementary image element cells across the security image area. Each of the complementary image element cells is divided into a plurality of pixels, such that each complementary image element cell defines a cell pixel array. The printed security image comprises image elements and complementary image elements.