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.

The present invention relates to a process for the preparation of thin silver nano-particles containing layers, which are produced directly on a substrate as part of a coating or printing process. The layers can show different colours in transmittance and reflectance. The invention further relates to decorative and security elements. When the layers are applied over a security element, such as a hologram, the obtained products may show different colours in reflection and transmission, an extremely bright optically variable image (OVD image). Depending on the thickness of the layer a more or less intensive metallic aspect appears.

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.

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.

The card comprises a first translucent or transparent substrate layer, preferably in PVC, and a second substrate layer, and a cracked layer of ink between the two substrate layers so as to allow the second substrate layer to show through the cracks of the layer of ink. The cracked layer of printing ink comprises mirror-effect ink, that reflects light through the first translucent or transparent substrate layer. The cracking of the layer of ink is achieved when the card is manufactured by laminating it.

The card comprises a first translucent or transparent substrate layer, preferably in PVC, and a second substrate layer, and a cracked layer of ink between the two substrate layers so as to allow the second substrate layer to show through the cracks of the layer of ink. The cracked layer of printing ink comprises mirror-effect ink, that reflects light through the first translucent or transparent substrate layer. The cracking of the layer of ink is achieved when the card is manufactured by laminating it.

An article including a magnetic-containing layer having a first surface and a second surface opposite the first; a first reflector layer external to the first surface of the magnetic-containing layer; a second reflector layer external to the second surface of the magnetic-containing layer; a first selective light modulator layer external to the first reflector layer; a second selective light modulator layer external to the second reflector layer; a first absorber layer external to the first selective light modulator layer; and a second absorber layer external to the second selective light modulator layer; wherein at least one of the first and second selective light modulator layers comprises at least one of a curing agent, and at least one coating aid is disclosed. Methods of making the disclosed article are also disclosed.

A multilayer identification patch comprises a reflective layer and a design layer on top of the reflective layer. The design layer comprises an opaque body and at least one identification symbol void (ISV) to allow light to reflect from a portion of the reflective layer via the ISV. The opaque body of the design layer comprises multiple layers of cured photopolymer ink. The multiple layers of cured photopolymer ink comprise an opaque layer of colored photopolymer ink. In one embodiment, the multiple layers of cured photopolymer ink in the opaque body of the design layer further comprise a layer of clear photopolymer ink under the opaque layer of colored photopolymer ink. Other embodiments are described and claimed.

A multilayer identification patch comprises a reflective layer and a design layer on top of the reflective layer. The design layer comprises an opaque body and at least one identification symbol void (ISV) to allow light to reflect from a portion of the reflective layer via the ISV. The opaque body of the design layer comprises multiple layers of cured photopolymer ink. The multiple layers of cured photopolymer ink comprise an opaque layer of colored photopolymer ink. In one embodiment, the multiple layers of cured photopolymer ink in the opaque body of the design layer further comprise a layer of clear photopolymer ink under the opaque layer of colored photopolymer ink. Other embodiments are described and claimed.