A method for marking a product (1) with a photoluminescent mark, said mark comprising a photoluminescent portion (10) which is transparent under normal light conditions and revealed by photoluminescence under UV illumination, said mark further comprising a non photoluminescent portion (9) which is transparent under normal light conditions as well as under UV illumination, said method comprising: deposing on said product a stack, said stack comprising alternatively layers (2, 4), such as AlN, with a thickness of less than 1 micron and layers (3) of a second material, such as GaN, with a thickness of less than 10 nm; raising the transparency of said non photoluminescent portion (10) with a deposition of transparent material (6) or incorporation of ions into said non photoluminescent portions.

A method for marking a product (1) with a photoluminescent mark, said mark comprising a photoluminescent portion (10) which is transparent under normal light conditions and revealed by photoluminescence under UV illumination, said mark further comprising a non photoluminescent portion (9) which is transparent under normal light conditions as well as under UV illumination, said method comprising: deposing on said product a stack, said stack comprising alternatively layers (2, 4), such as AlN, with a thickness of less than 1 micron and layers (3) of a second material, such as GaN, with a thickness of less than 10 nm; raising the transparency of said non photoluminescent portion (10) with a deposition of transparent material (6) or incorporation of ions into said non photoluminescent portions.

A method of illumating an item is disclosed. The method includes applying adhesive to the item, interspersing a taggant in the adhesive, illuminating the item with an excitation signal, sensing luminescence emitted by the taggant in response to illumination by the excitation signal, and determining the authenticity of the item based on the sensed emitted luminescence. The item can include any item benefited by authentication, and can include a postage stamp. A method of customizing an item is disclosed. This can include the steps of preparing a substrate, applying a security feature to the substrate, printing non-customized information on the substrate, receiving image information, and printing the image information on the substrate.

A method of illumating an item is disclosed. The method includes applying adhesive to the item, interspersing a taggant in the adhesive, illuminating the item with an excitation signal, sensing luminescence emitted by the taggant in response to illumination by the excitation signal, and determining the authenticity of the item based on the sensed emitted luminescence. The item can include any item benefited by authentication, and can include a postage stamp. A method of customizing an item is disclosed. This can include the steps of preparing a substrate, applying a security feature to the substrate, printing non-customized information on the substrate, receiving image information, and printing the image information on the substrate.

The present invention relates to the field of optical effect layers (OEL) comprising magnetically oriented non-spherical oblate magnetic or magnetizable pigment particles on a substrate, spinneable magnetic assemblies and processes for producing said optical effect layers (OEL). In particular, the present invention relates to spinneable magnetic assemblies and processes for producing said OELs as anti-counterfeit means on security documents or security articles or for decorative purposes.

The present invention relates to the field of optical effect layers (OEL) comprising magnetically oriented non-spherical oblate magnetic or magnetizable pigment particles on a substrate, spinneable magnetic assemblies and processes for producing said optical effect layers (OEL). In particular, the present invention relates to spinneable magnetic assemblies and processes for producing said OELs as anti-counterfeit means on security documents or security articles or for decorative purposes.

A credential with one or more security features is disclosed. The disclosed credential includes a windowed security feature. The windowed security feature is taught to include a mirror element positioned in proximity with a transparent window and a first photo-luminescent feature positioned relative to the transparent window and the mirror element such that the mirror element enhances a luminescence of the first photo-luminescent feature when viewed and illuminated through the transparent window.

A credential with one or more security features is disclosed. The disclosed credential includes a windowed security feature. The windowed security feature is taught to include a mirror element positioned in proximity with a transparent window and a first photo-luminescent feature positioned relative to the transparent window and the mirror element such that the mirror element enhances a luminescence of the first photo-luminescent feature when viewed and illuminated through the transparent window.

A method of illuminating an item is disclosed. The method includes applying adhesive to the item, interspersing a taggant in the adhesive, illuminating the item with an excitation signal, sensing luminescence emitted by the taggant in response to illumination by the excitation signal, and determining the authenticity of the item based on the sensed emitted luminescence. The item can include any item benefited by authentication, and can include a postage stamp. A method of customizing an item is disclosed. This can include the steps of preparing a substrate, applying a security feature to the substrate, printing non-customized information on the substrate, receiving image information, and printing the image information on the substrate.

A method of illuminating an item is disclosed. The method includes applying adhesive to the item, interspersing a taggant in the adhesive, illuminating the item with an excitation signal, sensing luminescence emitted by the taggant in response to illumination by the excitation signal, and determining the authenticity of the item based on the sensed emitted luminescence. The item can include any item benefited by authentication, and can include a postage stamp. A method of customizing an item is disclosed. This can include the steps of preparing a substrate, applying a security feature to the substrate, printing non-customized information on the substrate, receiving image information, and printing the image information on the substrate.