Security documents often incorporate optically variable devices to prevent or hinder counterfeiters. Disclosed herein are layered optically variable devices such as color-shift foils, and methods for their production and use. Such devices afford new techniques for a user of a security document to check quickly and easily whether the security document is a legitimate document or a counterfeit copy.

Security documents often incorporate optically variable devices to prevent or hinder counterfeiters. Disclosed herein are layered optically variable devices such as color-shift foils, and methods for their production and use. Such devices afford new techniques for a user of a security document to check quickly and easily whether the security document is a legitimate document or a counterfeit copy.

Environmental monitors for monitoring a predetermined environmental exposure, for example, an historical heat exposure such as a cumulative ambient heat exposure and/or a peak ambient heat exposure may include an environmental indicator material and a security material. The environmental monitor may be configured to attach to a host product for monitoring the predetermined environmental exposure of the host product, and additionally serve as an anti-counterfeiting indicator.

The present invention relates to the field of security inks suitable for printing security features on substrates, in particular on security documents or articles as well as security features made from said security inks, and security documents comprising a security feature made from said security inks. In particular, the invention provides UV-Vis radiation radically curable security inks comprising an ink vehicle and pigments comprising a flake-shaped non-metallic or metallic substrate comprising one or more at least partial coating layers, an at least partial surface treatment layer made of one or more surface modifiers selected from fluoro compounds.

The present invention relates to the field of security inks suitable for printing security features on substrates, in particular on security documents or articles as well as security features made from said security inks, and security documents comprising a security feature made from said security inks. In particular, the invention provides UV-Vis radiation radically curable security inks comprising an ink vehicle and pigments comprising a flake-shaped non-metallic or metallic substrate comprising one or more at least partial coating layers, an at least partial surface treatment layer made of one or more surface modifiers selected from fluoro compounds.

A display that exhibits improved anti-counterfeiting effects. The display includes an uneven-structure-forming layer having an uneven structure on one surface and a reflecting layer that covers at least part of an unevenly structured surface. In the display, the uneven-structure-forming layer includes a first region group including a plurality of first regions, each first region including a flat part and a plurality of convexities or a plurality of concavities, the top surface of each of the convexities or the bottom surface of each of the concavities is substantially parallel to a surface of the flat part; distances between the centers of adjacent convexities or concavities are not equal; the convexities have a uniform height, or the concavities have a uniform depth; the first region group is formed, with the first regions arrayed inside at a regular pitch.

A dielectric layer comprising an embossed surface and a flat surface which is located at a side opposite to the embossed surface is provided. The plane that approximates the flat surface is the X-Y plane, and the normal direction to the X-Y plane is the Z direction. The embossed surface has inclined surfaces that are inclined with respect to the Z direction, and the inclined surfaces reflect incident light incident on the dielectric layer and emerge reflected light. The elevation angle, which is an angle between the inclined surface and the X-Y plane, is α. The refractive index of the dielectric layer is n. These values satisfy Formula (1): sin α≤(1/n)<sin 2α.

Multilayered security devices comprising a patterned substrate over which a graphene-based coating has been applied.

Multilayered security devices comprising a patterned substrate over which a graphene-based coating has been applied.

The invention relates to a plasmonic optical security component comprising two layers (2, 4) made of transparent dielectric material and a metal layer (3) arranged between said transparent dielectric material layers in order to form two dielectric-metal interfaces (31, 32). The metal layer is structured to form, on a first coupling region, a first periodic, two-dimensional coupling array (C.sub.1) which is capable of coupling surface plasmon modes, which are supported by said dielectric-metal interfaces, to an incident light ray, the first coupling array having a profile which does not have point symmetry in any of the directions thereof, and, on a second coupling region, a second periodic, two-dimensional coupling array (C.sub.2) which is capable of coupling surface plasmon modes, which are supported by said dielectric-metal interfaces, to an incident light ray, the second coupling array having a profile which does not have point symmetry in any of the directions thereof and is different from that of the first coupling array.