Abstract: A system and method for determining which of a plurality of visually indistinguishable objects have been marked with a covert indicator in which a portion of a surface of each of a first type of objects are provided with a covert holographic indicator which is exposed to be viewed but which is detectable only when illuminated with a coherent reference light of predetermined wavelength. The surfaces of objects are scanned with a coherent reference light with the predetermined wavelength, and evaluated to determine whether the scanned surfaces include the covert holographic indicator. The presence of the covert holographic indicator indicates that the object on which the covert holographic indicator is detected is one of the first type of objects. The first type of object may be a winning game ticket, or a genuine, as opposed to counterfeit, article.

Abstract: A decorative sheet is formed of an oil absorbing substrate and an oil permeable decorative layer. The decorative layer is a porous oleophilic membrane formed from fused polymer particles. Fingerprints and other skin oil placed on the exposed surface of the decorative layer are absorbed into the sheet so that they do not appear on that surface and do not interfere with the optical effect of diffraction gratings or holograms thereon.

Abstract: A decorative sheet is formed of an oil absorbing substrate and an oil permeable decorative layer. The decorative layer is a porous oleophilic membrane formed from fused polymer particles. Fingerprints and other skin oil placed on the exposed surface of the decorative layer are absorbed into the sheet so that they do not appear on that surface and do not interfere with the optical effect of diffraction gratings or holograms thereon.

Abstract: A method for decoration of paper or plastic sheeting and other substrates, involving a novel technique for coating and embossing the substrate. The paper or plastic sheeting is supplied with a coating of thermosensitive material, as by extrusion. The coated sheet is heated to adequately soften the coating, such as by use of a heated cylinder, and remote heat sources such as infrared heaters. The softened sheet surface is then decorated using an embossing member, to provide a diffraction pattern or hologram. Use of an embossment pattern of lesser depth than the surface roughness of the sheet before embossing provides attractive decorative patterns.

Abstract: A decorative substrate consisting of a paper base sheet coated with a thermoplastic material, involving a novel technique for coating and embossing the substrate. The paper sheeting is supplied with a thermoplastic material, as by coating or extrusion. The coated sheet is heated to adequately soften the coating, such as by use of a heated cylinder, and remote heat sources such as infrared heaters. The softened sheet surface is then decorated using an embossing member, to provide a diffraction pattern or hologram. Use of an embossment pattern of lesser depth than the surface roughness of the sheet before embossing provides attractive decorative patterns.