A laser-assisted method embeds luminescent taggant particles in the surface of a substrate to provide a covert method of evaluating the authenticity of articles so treated.

The present invention provides an anti-counterfeit ink composition including organic-inorganic hybrid infrared absorbing particles, and either a dispersant or a surfactant, or both, wherein the organic-inorganic hybrid infrared absorbing particles include infrared absorbing particles and a coating resin that covers at least a part of a surface of the infrared absorbing particles.

The present invention relates to a layered composite comprising at least one transparent layer a) containing a thermoplastic, this transparent layer having a light transmission in the range of from ≥85% to ≤98% determined according to ISO 13468-2:2006-07, and an opaque layer b) containing at least one thermoplastic, characterised in that the opaque layer b) has a light transmission in the range of from ≥0.1% to ≤25% determined according to ISO 13468-2:2006-07, a layer thickness in the range of from ≥20 μm to ≤70 μm, preferably from ≥20 μm to ≤60 μm, particularly preferably from ≥25 μm to ≤55 μm, and at least one opening.

An identification patch having a pattern of plasmonic resonance elements may be used to ensure that an article is counterfeit-proof. The identification patch is formed by laser-induced superplasticity to create a distinctive pattern of resonance elements that each contain a plurality of nanostructures. When the identification patch is irradiated, the pattern of resonance elements produces a unique spectral response that is associated only with the counterfeit-proof article. The counterfeit-proof article may be a metal component or an integrated circuit. The resonant absorption of the plasmonic resonance elements may be measured to verify the authenticity of the article before use of the article.

In a printed article, pigment flakes are magnetically aligned so as to form curved patterns in a plurality of cross-sections normal a continuous imaginary line, wherein radii of the curved patterns increase along the imaginary line from the first point to the second point. When light is incident upon the aligned pigment flakes from a light source, light reflected from the aligned pattern forms a bright image which appears to gradually change its shape and move from one side of the continuous imaginary line to another side of the continuous imaginary line when the substrate is tilted with respect to the light source.

In a printed article, pigment flakes are magnetically aligned so as to form curved patterns in a plurality of cross-sections normal a continuous imaginary line, wherein radii of the curved patterns increase along the imaginary line from the first point to the second point. When light is incident upon the aligned pigment flakes from a light source, light reflected from the aligned pattern forms a bright image which appears to gradually change its shape and move from one side of the continuous imaginary line to another side of the continuous imaginary line when the substrate is tilted with respect to the light source.

Examples described herein relate to a system consistent with the disclosure. For instance, the system may comprise a printing device including hardware to form an image on a print medium, a memory resource, and a controller to receive a print job to form the markings on the print medium, designate a pixel of the received print job to form a covert dot pattern on the markings, where the pixel corresponds to a first laser intensity level; and adjust a laser intensity of the printing device to a second laser intensity level based on the first laser intensity level of the designated pixel to form the covert dot pattern.

A flake including a layer of a diamagnetic material; and at least one additional layer is disclosed. The flake, such as a plurality of flakes, can be dispersed in a liquid medium to form a composition. The composition can be applied to a surface of a substrate to form a security device. A method of making the security device is also disclosed.

According to examples, a substrate may be moved through a magnetic field, in which the substrate includes a fluid carrier containing magnetically-orientable flakes. The magnetic field may influence the magnetically-orientable flakes to be respectively oriented in one of multiple orientations. In addition, during movement of the substrate through the magnetic field, radiation may be applied onto a plurality of selected portions of the fluid carrier through at least one opening in a mask to cure the fluid carrier at the plurality of selected portions and fix the magnetically-orientable flakes in the plurality of selected portions at the respective angular orientations as influenced by the magnetic field.

According to examples, a substrate may be moved through a magnetic field, in which the substrate includes a fluid carrier containing magnetically-orientable flakes. The magnetic field may influence the magnetically-orientable flakes to be respectively oriented in one of multiple orientations. In addition, during movement of the substrate through the magnetic field, radiation may be applied onto a plurality of selected portions of the fluid carrier through at least one opening in a mask to cure the fluid carrier at the plurality of selected portions and fix the magnetically-orientable flakes in the plurality of selected portions at the respective angular orientations as influenced by the magnetic field.