Microstructured pigments include a dielectric core having a diffraction grating. The microstructured dielectric core is encapsulated with one or more encapsulation layers which are deposited using chemical vapor deposition in a fluidized bed. The fluidizing conditions allow for providing uniform and highly-conforming encapsulation layers.

A diffractive pigment blend or composition is provided which includes a plurality of groups of all-dielectric diffractive pigment flakes. The pigment flakes of each group each include one or more dielectric layers for providing a background color, at least one of which includes a diffractive structure for providing a diffractive effect. Each group of pigment flakes provides a different diffractive effect, and the diffractive pigment blend or composition provides a combined diffractive effect that is a combination of the different diffractive effects. The combined diffractive effect may be a neutral white diffractive effect or may include a reversal in color travel.

A volume diffractive optical element (E) comprising: a carrier (1) having an optical relief pattern (P) on at least one surface thereof, and at least one optically functional layer (2) applied over or onto at least one or more portions or relief features (P) of the relief pattern on the carrier (1); wherein in embodiments the at least one optically functional layer (2) comprises a plurality of discrete bodies, beads or globules (2) of optical material applied over or onto the respective individual relief portions or relief features or relief elements (P) of the relief pattern on the carrier (1).

A diffractive pigment blend or composition is provided which includes a plurality of groups of all-dielectric diffractive pigment flakes. The pigment flakes of each group each include one or more dielectric layers for providing a background color, at least one of which includes a diffractive structure for providing a diffractive effect. Each group of pigment flakes provides a different diffractive effect, and the diffractive pigment blend or composition provides a combined diffractive effect that is a combination of the different diffractive effects. The combined diffractive effect may be a neutral white diffractive effect or may include a reversal in color travel.

A security device has a support substrate of a first material having a softening temperature t1 and an embossed layer of a second different material supported by the support substrate having a softening temperature t2, wherein t2<t1. A thin film coating deposited directly upon the embossed layer, wherein the embossed layer is capable of being dissolved in a dissolving agent and wherein the thin film coating is not dissolvable by said dissolving agent. There is not need for an additional release layer as the second different material is dissolvable and allows flakes to be formed by dissolving the second layer.

A color shifting security device has a Fabry-Perot type structure wherein a dielectric layer is disposed between a reflector and an absorbing layer. The absorber and reflector layers may be conforming and the dielectric layer therebetween is non-conforming, filling the regions in the micro structured adjacent absorbing or reflecting layer, at least one of which has a microstructure therein or thereon. By having the dielectric layer not conform to the microstructure it is next to, its thickness varies in cross section, which allows for different colors to be seen where the thickness varies.

Metallic coatings containing metallic flakes with optical coatings are provided. The metallic flakes can be coated with multiple optical layers or a photonic crystal layer. The metallic flakes can also be coated with a pigment layer.

A diffractive pigment blend or composition is provided which includes a plurality of groups of all-dielectric diffractive pigment flakes. The pigment flakes of each group each include one or more dielectric layers for providing a background color, at least one of which includes a diffractive structure for providing a diffractive effect. Each group of pigment flakes provides a different diffractive effect, and the diffractive pigment blend or composition provides a combined diffractive effect that is a combination of the different diffractive effects. The combined diffractive effect may be a neutral white diffractive effect or may include a reversal in color travel.

Microstructured pigments include a dielectric core having a diffraction grating. The microstructured dielectric core is encapsulated with one or more encapsulation layers which are deposited using chemical vapor deposition in a fluidized bed. The fluidizing conditions allow for providing uniform and highly-conforming encapsulation layers.

A color shifting security device has a Fabry-Perot type structure wherein a dielectric layer is disposed between a reflector and an absorbing layer. The absorber and reflector layers may be conforming and the dielectric layer therebetween is non-conforming, filling the regions in the micro structured adjacent absorbing or reflecting layer, at least one of which has a microstructure therein or thereon. By having the dielectric layer not conform to the microstructure it is next to, its thickness varies in cross section, which allows for different colors to be seen where the thickness varies.