A method for manufacturing a two-dimensional colored bar code comprising an arrangement of colored basic structural elements encoding at least one information element, the manufacturing method comprising determining, by data processing means, a set of colored basic structural elements corresponding to the at least one information element, at least one structural element of the set comprising a pattern; and forming the at least one structural element of the set on a backing, in order to create the arrangement of colored basic structural elements.

A security sheet including at least one paper substrate, at least one watermark produced in the paper substrate, the watermark having an exterior outline, at least one aperture of regular edge, produced by ablation of the paper substrate, and at least one security film that is at least partially superposed on the watermark and on the aperture. In the sheet, the at least one aperture lies inside the watermark, such as bounded by its exterior outline.

A security sheet including at least one paper substrate, at least one watermark produced in the paper substrate, the watermark having an exterior outline, at least one aperture of regular edge, produced by ablation of the paper substrate, and at least one security film that is at least partially superposed on the watermark and on the aperture. In the sheet, the at least one aperture lies inside the watermark, such as bounded by its exterior outline.

A prism layer has an uneven surface that includes at least one display region. An interface layer is adjacent to the uneven surface. The interface layer has a difference in refractive index from the prism layer such that a refractive index of a side of an interface between the uneven surface and the interface layer at which the prism layer is located is higher than a refractive index of a side of the interface at which the light interference layer is located. The display region includes inclination elements. The inclination elements adjacent to each other in an array direction contact each other in a plan view facing a plane along which the prism layer expands. The inclination elements include first inclination elements among which the inclination angle increases by the even angles along the array direction.

An optical device is formed by hot stamping a demetallized hologram to an optically variable foil or to a coating of optically variable ink. In another embodiment a hologram is hot stamped to a banknote or document printed with a color-shifting ink.

Systems, methods and apparatus are provided for light-based authentication of a payment card. The payment card may include a randomized mix of materials. The materials may include transparent or translucent materials. A light source may shine light on a surface of the payment card. Light passing through the card may generate a light pattern that is unique to the payment card. The light pattern may be captured and compared to a reference light pattern to authenticate the payment card. In some embodiments, photodetectors may detect light patterns generated through interactions with the card materials.

Systems, methods and apparatus are provided for light-based authentication of a payment card. The payment card may include a randomized mix of materials. The materials may include transparent or translucent materials. A light source may shine light on a surface of the payment card. Light passing through the card may generate a light pattern that is unique to the payment card. The light pattern may be captured and compared to a reference light pattern to authenticate the payment card. In some embodiments, photodetectors may detect light patterns generated through interactions with the card materials.

Provided are an optical anti-counterfeiting element and an anti-counterfeiting product. The optical anti-counterfeiting element comprises: a substrate, which comprises a first surface and second surface that are opposite one another; and a surface micro-structure layer that is formed on at least part of the first surface of the substrate. At least part of the surface micro-structure layer comprises a first set of at least a micro-prism, and the micro-prism is simultaneously provided with a refractive and a reflective function. Each pixel of a first pattern corresponds to one or more micro-prism refractive illumination spots in the first set of micro-prisms. The described optical anti-counterfeiting element can provide various anti-counterfeiting effects and improve the anti-counterfeiting performance of the anti-counterfeiting element.

A security document (200) includes a secure substrate (205). The secure substrate includes a viewing side (209) and a backing side (211), and a micro-optic system (305, 321) providing an optically variable effect (OVE) (513) on the viewing side. The security document further includes a protective layer (225), and a mask layer (215) disposed between the protective layer and the backing side of the secure substrate.

A security document (200) includes a secure substrate (205). The secure substrate includes a viewing side (209) and a backing side (211), and a micro-optic system (305, 321) providing an optically variable effect (OVE) (513) on the viewing side. The security document further includes a protective layer (225), and a mask layer (215) disposed between the protective layer and the backing side of the secure substrate.