Abstract: Various methods of producing a security document or article including a diffractive optical microstructure are disclosed. One method includes applying an opacifying layer (102) to at least one surface of a transparent substrate (100). An area of the opacifying layer (102) is exposed to laser radiation (108) to ablate apertures (110) in selected portions of the opacifying layer (102), thereby forming a diffractive optical microstructure (112) on the surface of the substrate (100). The laser radiation may be patterned prior to exposing the opacifying layer (102), for example by passing the radiation through a mask (104). Alternatively, a focussed or collimated laser beam (206) may be directed onto the selected portions of the opacifying layer (102). Laser radiation may be directed onto the opacifying layer (102) either directly, or through the transparent substrate (100). Security documents or articles made in accordance with the method are also provided.

Abstract: A self-verifying security document, such as a banknote, comprises a flexible sheet formed from a plastics substrate bearing indicia. The sheet has a window of transparent plastics material that includes self-verification means for verifying a security device provided at a laterally spaced second portion of the sheet when the sheet is bent or folded to bring the window into register with the security device. The self-verification means may be an optical lens for reading an area of microprinting. In another embodiment, the self-verification means may be an optical filter for viewing an area printed with metameric inks. In other embodiments, the self-verification means and the security device may be polarizing windows or Moire inducing patterns.

Abstract: A printed document or other device comprising a polymer substrate having a surface to which printed matter is applied, a reflective or brightly colored layer applied directly to said surface by means of a printing process, and a printed image applied to the reflective or brightly colored layer by an intaglio printing process.

Abstract: Method of verifying the authenticity of a security document (1), the security document including a first at least partially transparent portion (7, 8) and an optical projection element (9) within or superposed with the first at least partially transparent portion (7, 8), the optical projection element (9) acting to transform a light beam (10a) passing from a light beam source through said first at least partially transparent portion (7, 8) into a patterned beam (11) of selected design, the method including the steps of: positioning the security document such that the light beam is transmitted through the first at least partially transparent portion and the patterned beam is projected onto a viewing surface (14), and verifying the presence of a patterned image by the impingement of the patterned beam on the viewing surface (14).

Abstract: Method of verifying the authenticity of a security document (1), the security document including a first at least partially transparent portion (7, 8) and an optical projection element (9) within or superposed with the first at least partially transparent portion (7, 8), the optical projection element (9) acting to transform a light beam (10a) passing from a light beam source through said first at least partially transparent portion (7, 8) into a patterned beam (11) of selected design, the method including the steps of positioning the security document such that the light beam is transmitted through the first at least partially transparent portion and the patterned beam is projected onto a viewing surface (14), and verifying the presence of a patterned image by the impingement of the patterned beam on the viewing surface (14).

Abstract: Method of verifying the authenticity of a security document (1), the security document including a first at least partially transparent portion (7, 8) and an optical projection element (9) within or superposed with the first at least partially transparent portion (7, 8), the optical projection element (9) acting to transform a light beam (10a) passing from a light beam source through said first at least partially transparent portion (7, 8) into a patterned beam (11) of selected design, the method including the steps of: positioning the security document such that the light beam is transmitted through the first at least partially transparent portion and the patterned beam is projected onto a viewing surface (14), and verifying the presence of a patterned image by the impingement of the patterned beam on the viewing surface (14).

Abstract: A self-verifying security document, such as a banknote, comprises a flexible sheet formed from a plastics substrate bearing indicia. The sheet has a window of transparent plastics material which includes self-verification means for verifying a security device provided at a laterally spaced second portion of the sheet when the sheet is bent or folded to bring the window into register with the security device. The self-verification means may be an optical lens for reading an area of microprinting. In another embodiment, the self-verification means may be an optical filter for viewing an area printed with metameric inks. In other embodiments, the self-verification means and the security device may be polarizing windows or Moire inducing patterns.

Abstract: A self-verifying security document, such as a banknote (1) comprises a flexible sheet formed from a plastics substrate (2) bearing indicia (3). The sheet has a window (5) of transparent plastics material which includes self-verification means (11) for verifying a security device (4) provided at a laterally spaced second portion of the sheet when the sheet is bent or folded to brings the window (5) into register with the security device (4). The self-verification means may be an optical lens (11) for reading an area of microprinting (10). In another embodiment, the self-verification means may be an optical filter (21) for viewing an area (22) printed with metameric inks. In other embodiments, the self-verification means and the security device (4) may be polarising windows (31, 32) or Moire inducing patterns (41, 42).

Abstract: A self-verifying security document, such as a banknote (1) comprises a flexible sheet formed from a plastics substrate (2) bearing indicia (3). The sheet has a window (5) of transparent plastics material which includes self-verification means (11) for verifying a security device (4) provided at a laterally spaced second portion of the sheet when the sheet is bent or folded to bring the window (5) into register with the security device (4). The self-verification means may be an optical lens (11) for reading an area of microprinting (10). In another embodiment, the self-verification means may be an optical filter (21) for viewing an area (22) printed with metameric inks. In other embodiments, the self-verification means and the security device (4) may be polarising windows (31, 32) or Moire inducing patterns (41, 42).

Abstract: A security document or device having a substrate (2), a smooth highly reflective layer (1) applied to the substrate (2) and having a reflectivity of at least 60 gloss units, a raised printed image (3) of lines or dots applied to said reflective layer (1) by a printing process and having a height of about 10 to 100 &mgr;m, and typically about 30 &mgr;m, and a similar spacing being adjacent lines or dots, the hue chroma value of the ink used to print the image being between 30 and about 50 chroma units tending towards a saturation value of 60 chroma units, the lightness of the ink being at least 50 L degrees (lightness units), and typically between 70 and 100 L degrees.

Abstract: Security document (1) with security indicia (21) for preventing unauthorised reproduction, the security indicia being detectable in transmitted light, wherein the security indicia are located within the bounds of a security pattern (20) acting to visually conceal the security pattern in reflected light. The security pattern may be formed of one or more elements (25) and may have a complexity selected to enable the concealment of the security indicia (21).

Abstract: A self-verifying security document, such as a banknote (1) comprises a flexible sheet formed from a plastics substrate (2) bearing indicia (3). The sheet has a window (5) of transparent plastics material which includes self-verification means (11) for verifying a security device (4) provided at a laterally spaced second portion of the sheet when the sheet is bent or folded to bring the window (5) into register with the security device (4). The self-verification means may be an optical lens (11) for reading an area of microprinting (10). In another embodiment, the self-verification means may be an optical filter (21) for viewing an area (22) printed with metameric inks. In other embodiments, the self-verification means and the security device (4) may be polarizing windows (31, 32) or Moire inducing patterns (41, 42).

Abstract: A security document (1), such as a bank note, is formed from a sheet-like substrate (10) of clear plastic material with layers (13, 14, 15, 16) of opacifying ink applied to the surfaces (11, 12) of the substrate (10). The security document (1) includes a security device (20) which is at least partially obscured by the layers (13, 14) of opacifying ink on a flat surface (11) of the substrate (10). The layers (15, 16) on the second surface (12) of the substrate (10) are applied in such a manner so as to leave a “half-window” area uncovered by opacifying ink through which the security device (20) is visible for one side of the document (1). The security device (20) may extend transversely outside the half-window area and be visible in transmission, enabling a different contrasting effect to be observed from both sides of the document.

Abstract: A security document (1), such as a bank note, is formed from a sheet-like substrate (10) of clear plastic material with layers (13, 14, 15, 16) of opacifying ink applied to the surfaces (11, 12) of the substrate (10). The security document (1) includes a security device (20) which is at least partially obscured by the layers (13, 14) of opacifying ink on a flat surface (11) of the substrate (10). The layers (15, 16) on the second surface (12) of the substrate (10) are applied in such a manner so as to leave a “half-window” area uncovered by opacifying ink through which the security device (20) is visible for one side of the document (1). The security device (20) may extend transversely outside the half-window area and be visible in transmission, enabling a different contrasting effect to be observed from both sides of the document.

Abstract: A self-verifying security document, such as a banknote, comprises a flexible sheet formed from a plastics substrate bearing indicia. The sheet has a window of transparent plastics material which includes self-verification means for verifying a security device provided at a laterally spaced second portion of the sheet when the sheet is bent or folded to bring the window into register with the security device. The self-verification means may be an optical lens for reading an area of microprinting. In another embodiment, the self-verification means may be an optical filter for viewing an area printed with metameric inks. In other embodiments, the self-verification means and the security device may be polarizing windows or Moire inducing patterns.

Abstract: One aspect of the present invention provides a method of producing a security document, including the steps of: (a) forming a sheet-like substrate of plastics material having first and second opposing surfaces, (b) coating a first layer of polymer material containing magnetic particles on the first opposing surface, (c) melting at least a portion of the first layer such that the magnetic particles can orient under the influence of a magnetic field, (d) applying the magnetic field so as to form a magnetic watermark, and (e) allowing the first layer portion to cool so as to fix the orientation of the magnetic particles

Abstract: A method of marking or forming a transparent window in an article 6, such as a security document, is provided in which areas of opacifying layers of printed ink 8, 10 on opposite surfaces of a polymeric film or substrate 12 are irradiated by laser radiation 4 of a selected wavelength. The opacifying layers 8, 10 have greater absorption characteristics for the laser radiation than the film or substrate 12 which is substantially transparent to the selected wavelength of the laser radiation so that after ablation of the area of printed matter 8 on one surface, the radiation passes through the substrate 12 substantially unaffected to ablate the area of printed matter 10 on the opposite surface. In the resultant article, the markings or windows formed by the areas of printing removed from each surface of the substrate 12 are in register, and provide a deterrent against counterfeiting.

Abstract: A security document (1), such as a bank note, is formed from a sheet-like substrate (10) of clear plastic material with layers (13, 14, 15, 16) of opacifying ink applied to the surfaces (11, 12) of the substrate (10). The security document (1) includes a security device (20) which is at least partially obscured by the layers (13, 14) of opacifying ink on a flat surface (11) of the substrate (10). The layers (15, 16) on the second surface (12) of the substrate (10) are applied in such a manner so as to leave a “half-window” area uncovered by opacifying ink through which the security device (20) is visible for one side of the document (1). The security device (20) may extend transversely outside the half-window area and be visible in transmission, enabling a different contrasting effect to be observed from both sides of the document.

Abstract: A self-verifying security document, such as a banknote (1) comprises a flexible sheet formed from a plastics substrate (2) bearing indicia (3). The sheet has a window (5) of transparent plastics material which includes self-verification means (11) for verifying a security device (4) provided at a laterally spaced second portion of the sheet when the sheet is bent or folded to bring the window (5) into register with the security device (4). The self-verification means may be an optical lens (11) for reading an area of microprinting (10). In another embodiment, the self-verification means may be an optical filter (21) for viewing an area (22) printed with metameric inks. In other embodiments, the self-verification means and the security device (4) may be polarizing windows (31, 32) or Moire inducing patterns (41, 42).

Abstract: A self-verifying security document, such as a banknote (1) comprises a flexible sheet formed from a plastics substrate (2) bearing indicia (3). The sheet bas a window (5) of transparent plastics material which includes self-verification means (11) for verifying a security device (4) provided at a laterally spaced second portion of the sheet when the sheet is bent or folded to bring the window (5) into register with the security device (4). The self-verification means may be an optical lens (11) for reading an area of microprinting (10). In another embodiment, the self-verification means may be an optical filter (21) for viewing an area (22) printed with metameric inks. In other embodiments, the self-verification means and the security device (4) may be polarising windows (31, 32) or Moire inducing patterns (41, 42).