A security system, such as a banknote, comprises: i) a substrate, ii) a first ink, which is applied on at least a part of at least one surface of the substrate, wherein the first ink includes at least one IR luminescent dye and/or at least one IR luminescent pigment, and iii) a second non-luminescent ink, which is applied on at least a part of at least one surface of the substrate onto which the first ink is/are applied, wherein the second ink includes at least one non-luminescent IR absorbing pigment and/or a least one non-luminescent IR absorbing dye, wherein the first ink and the second ink at least partially overlap on the at least one surface of the substrate, wherein the second ink is applied in the overlapping area onto the first ink, and wherein the emission spectrum of the first ink and the absorption spectrum of the second ink at least partially overlap.

Described is a chiral liquid crystal polymer (CLCP) layer or pattern which comprises randomly distributed craters of controlled mean diameter and/or density. The density and/or mean diameter of the craters can be controlled, for example, by adjusting the wetting of a substrate by a CLCP precursor composition, the development time of the precursor composition, and the thickness of the applied precursor composition.

Described is a chiral liquid crystal polymer (CLCP) layer or pattern which comprises randomly distributed craters of controlled mean diameter and/or density. The density and/or mean diameter of the craters can be controlled, for example, by adjusting the wetting of a substrate by a CLCP precursor composition, the development time of the precursor composition, and the thickness of the applied precursor composition.

Optical device, and preferably a security device for a security document, and methods for the production thereof, the device including a diffractive optical element (DOE) including a plurality of subregions, wherein each subregion is configured to produce a projected image corresponding to a frame of an animation, wherein the animation includes both a static component and a variable component, and wherein the sub-regions are arranged such that when the DOE is illuminated by a point light source and moved in at least one direction, the animation is viewable as a projected image.

A security system, such as a banknote, comprises: i) a substrate, ii) a first ink, which is applied on at least a part of at least one surface of the substrate, wherein the first ink includes at least one IR luminescent dye and/or at least one IR luminescent pigment, and iii) a second non-luminescent ink, which is applied on at least a part of at least one surface of the substrate onto which the first ink is/are applied, wherein the second ink includes at least one non-luminescent IR absorbing pigment and/or a least one non-luminescent IR absorbing dye, wherein the first ink and the second ink at least partially overlap on the at least one surface of the substrate, wherein the second ink is applied in the overlapping area onto the first ink, and wherein the emission spectrum of the first ink and the absorption spectrum of the second ink at least partially overlap.

An adhesive suitable for use in security documents (for example, currency, passports, tickets, etc.) includes a plurality of polymers, that collectively exhibit tackification, resistance to aqueous agents, and solvent resistance, and a cross-linker selected to be activated to chemically react with one or more polymers of the plurality of polymers, at a temperature in a predetermined range of temperatures.

An adhesive suitable for use in security documents (for example, currency, passports, tickets, etc.) includes a plurality of polymers, that collectively exhibit tackification, resistance to aqueous agents, and solvent resistance, and a cross-linker selected to be activated to chemically react with one or more polymers of the plurality of polymers, at a temperature in a predetermined range of temperatures.

Information is written onto the surface of an object using both an optically identifiable pattern and subregions that exhibit differing magnetic properties. The optically identifiable pattern is printed onto a printed region on the surface of the object using a printing medium that contains magnetic particles. The printed region includes both a first subregion that exhibits a first prevailing magnetization direction and a second subregion that exhibits a second prevailing magnetization direction. The first magnetization direction differs from the second magnetization direction. The first and second magnetization directions are imparted to the first and second subregions by magnetic fields being applied to the magnetic particles. An edge between the first subregion and the second subregion does not coincide with any boundary of the optically identifiable pattern. The printed region contains both optically encoded information and magnetically encoded information. Additional information is decoded using both the optically and magnetically encoded information.

Information is written onto the surface of an object using both an optically identifiable pattern and subregions that exhibit differing magnetic properties. The optically identifiable pattern is printed onto a printed region on the surface of the object using a printing medium that contains magnetic particles. The printed region includes both a first subregion that exhibits a first prevailing magnetization direction and a second subregion that exhibits a second prevailing magnetization direction. The first magnetization direction differs from the second magnetization direction. The first and second magnetization directions are imparted to the first and second subregions by magnetic fields being applied to the magnetic particles. An edge between the first subregion and the second subregion does not coincide with any boundary of the optically identifiable pattern. The printed region contains both optically encoded information and magnetically encoded information. Additional information is decoded using both the optically and magnetically encoded information.

An article for laser marking can comprising: a thermoplastic composition comprising a thermoplastic polymer, an active component comprising at least one of a polymeric unit and an additive, wherein the thermoplastic polymer has a visible transmission of greater than or equal to 80% according to ASTM D1003-00, Procedure A, using D65 illumination, 10 degrees observer, and thickness of 1 mm; and a mark produced by chemical rearrangement of the active component generated by a laser of a first wavelength; wherein the mark exhibits at least one of: (i) a change in optical properties in the region 400 nm to 700 nm when exposed to light having a wavelength less than or equal to 500 nm; and (ii) a change in optical properties in the region of 400 nm to 700 nm when exposed to light having a wavelength greater than or equal to the first wavelength.