A sheet, including a substrate having a surface, wherein the surface includes a first marking that defines a boundary of a hollow flake, and a second marking that defines a boundary of a solid flake; wherein the first marking and the second marking are each, independently, configured to protrude from a plane of the surface or depress down from the plane of the surface; and wherein the first marking surrounds the second marking is disclosed. A complementary set of flakes, and a method of making the complementary set of flakes are also disclosed.

A sheet, including a substrate having a surface, wherein the surface includes a first marking that defines a boundary of a hollow flake, and a second marking that defines a boundary of a solid flake; wherein the first marking and the second marking are each, independently, configured to protrude from a plane of the surface or depress down from the plane of the surface; and wherein the first marking surrounds the second marking is disclosed. A complementary set of flakes, and a method of making the complementary set of flakes are also disclosed.

Manufacturing a discretized optical security microstructure on a substrate includes providing an ink into one or more cavities of a shim, the one or more cavities of the shim represent the discretized optical security microstructure, pressing the shim against the substrate, and removing the shim from the substrate. The shim is removed from the substrate such that the ink remains on a surface of the substrate forming the discretized optical security microstructure.

The shim includes a number of cavities. The characteristic size of an individual cavity is from 80 μm to 50 cm and the depth is from 300 nm to 100 μm. The cavities of the shim represent a discretized optical security microstructure representing diffractive or another optically active surface, preferably in a form of macro and/or micro relief, or simply curved shape with or without grating/hologram micro relief.

A blister pack includes a housing having a plurality of cavities and a multi-layer film sealed to the housing and enclosing the cavities, the multi-layer film including a base layer, at least one security element, and a heat protective layer. The heat protective layer is comprised of one of an amorphous polymer material or a semi-crystalline polymer material and is positioned to insulate the at least one security element from heat applied to the heat protective layer during heat sealing of the multi-layer film to the housing, the heat protective layer functioning as a heat sink for protection of the at least one security element during heat sealing of the multi-layer film to the housing.

An IR and/or UV machine-readable optical security device (e.g., micro-optic security thread) that is made up of at least one IR-absorbing component with a characteristic IR signature detectable at two or more IR-wavelengths, at least one UV-absorbing component with a characteristic UV signature detectable at two or more UV-wavelengths, at least one IR-absorbing component that absorbs IR light and emits light at a different invisible wavelength, at least one UV-absorbing component that absorbs UV light and emits light at a different invisible wavelength, or a combination thereof, is provided. The IR and UV machine-readable features do not interfere with the optical effects projected by the optical material.

A security element including a first layer having a first surface, an array of image regions across the surface, each including at least first and second sub-regions, a first array of plasmonic nanostructures in or on the surface across the first sub-regions, defining in each a corresponding portion of a first image, a second array across the second sub-regions, defining in each a corresponding portion of a second image; wherein each sub-region has a respective average inclination and the average inclinations of the first sub-regions are such that the first image is displayed at least at a first viewing angle and those of the second sub-regions are such that the second image is displayed at least at a second viewing angle different from the first and the second image is substantially not or only partially displayed at least at the first angle. Also, a method of manufacturing the security element.

A security element including a first layer having a first surface, an array of image regions across the surface, each including at least first and second sub-regions, a first array of plasmonic nanostructures in or on the surface across the first sub-regions, defining in each a corresponding portion of a first image, a second array across the second sub-regions, defining in each a corresponding portion of a second image; wherein each sub-region has a respective average inclination and the average inclinations of the first sub-regions are such that the first image is displayed at least at a first viewing angle and those of the second sub-regions are such that the second image is displayed at least at a second viewing angle different from the first and the second image is substantially not or only partially displayed at least at the first angle. Also, a method of manufacturing the security element.

A method for producing a multilayer body, with the steps of: a) providing a substrate film with a replication layer; b) molding a surface relief appearing to the observer in the form of a three-dimensional free-form surface, which is formed in particular by structures with a lens-like design generating a magnifying, demagnifying or distorting effect, into a surface of the replication layer; c) applying a first metal layer to the surface of the replication layer forming the surface relief; d) wet-chemically applying an at least partially transparent spacer layer to the metal layer; e) applying a second metal layer to the spacer layer.

A method for producing a multilayer body, with the steps of: a) providing a substrate film with a replication layer; b) molding a surface relief appearing to the observer in the form of a three-dimensional free-form surface, which is formed in particular by structures with a lens-like design generating a magnifying, demagnifying or distorting effect, into a surface of the replication layer; c) applying a first metal layer to the surface of the replication layer forming the surface relief; d) wet-chemically applying an at least partially transparent spacer layer to the metal layer; e) applying a second metal layer to the spacer layer.

A micro-optic security device with zonal color transitions includes a planar array of focusing elements, an image icon layer including a plurality of retaining structures, the plurality of retaining structures defining isolated volumes at a first depth within the image icon layer, a first zone of image icons, the first zone of image icons having a first predefined subset of the plurality of retaining structures, wherein the isolated volumes of retaining structures of the first predefined subset of the plurality of retaining structures contain cured pigmented material of a first color, and a second zone of image icons, the second zone of image icons including a second predefined subset of the plurality of retaining structures, wherein the isolated volumes of retaining structures of the second predefined subset of the plurality of retaining structures contain cured pigmented material of a second color, wherein the second color contrasts with the first color.