Abstract: A non-embossed security foil formed by a first taggant and a second taggant each positioned on a metallic surface and optically reactive to different stimuli for confirming the authenticity of important documents is provided. Each taggant defines a different color when exposed to an associated optical stimulus such as an infrared (IR) laser pen, allowing for the creation of multiple color, in register indicia or images that are covertly embedded into official documents and which are otherwise invisible to the naked eye. A method of utilizing taggants that are optically reactive to stimuli of different wavelengths is also provided.

Abstract: A non-embossed security foil formed by a first taggant and a second taggant each positioned on a metallic surface and optically reactive to different stimuli for confirming the authenticity of important documents is provided. Each taggant defines a different color when exposed to an associated optical stimulus such as an infrared (IR) laser pen, allowing for the creation of multiple color, in register indicia or images that are covertly embedded into official documents and which are otherwise invisible to the naked eye. A method of utilizing taggants that are optically reactive to stimuli of different wavelengths is also provided.

Abstract: Taggant fibers and methods of use provide for enhanced protection and security when the fibers are used in documents such as land titles, currency, passports and other documents of value. The taggant fibers consist of a minimum of two separate zones with each zone containing a different taggant to emit different wave lengths when excited. The taggants may consist of organic or inorganic compounds as are conventionally known and can be manufactured using for example polymeric materials which can be extruded during the fiber manufacturing process. Authentication of the fibers or documents containing such fibers can be readily viewed using conventional techniques.

Abstract: Taggant fibers and methods of use provide for enhanced protection and security when the fibers are used in documents such as land titles, currency, passports and other documents of value. The taggant fibers consist of a minimum of two separate zones with each zone containing a different taggant to emit different wave lengths when excited. The taggants may consist of organic or inorganic compounds as are conventionally known and can be manufactured using for example polymeric materials which can be extruded during the fiber manufacturing process. A first zone may comprise a fiber sheath which includes a taggant and a second or inner zone or core which may be formed into a company logo having letters with different or the same taggants. Authentication of the fibers or documents containing such fibers can be readily viewed using conventional techniques.

Abstract: Taggant fibers and methods of use provide for enhanced protection and security when the fibers are used in documents such as land titles, currency, passports and other documents of value. The taggant fibers consist of a minimum of two separate zones with each zone containing a different taggant to emit different wave lengths when excited. The taggants may consist of organic or inorganic compounds as are conventionally known and can be manufactured using for example polymeric materials which can be extruded during the fiber manufacturing process. Authentication of the fibers or documents containing such fibers can be readily viewed using conventional techniques.

Abstract: An object of this invention is to provide a method of producing printing with a hidden image which cannot be observed with the unaided eye but which can be observed by use of a tool to determine the authenticity of a document.In accordance with the invention, the lithographic printing process is used in conjunction with tints or halftones to produce a printed document having an image therein which is not detectable with the unaided eye, but which may be observed when the print is viewed through a tint screen. The hidden image is produced by making a composite negative comprising an exposure through a negative containing the image and a tint oriented at a first angle onto a piece of film, and then making a second exposure through a positive containing the image and a tint oriented at a second angle onto the same piece of film. The composite negative is enlarged and dots in the area of the intersection of the image and background are blended to hide the image.