Abstract: A metameric optical structure is disclosed having first optical structures comprising diffractive flakes having diffractive structures thereon, and a second optical structures having non-diffractive flakes which may have other special effect properties, such as color shifting. At one angle of incidence or one viewing angle, near normal. The hues match and at other angles they do not match. The diffractive flakes are preferably magnetically aligned so that the grating structures are parallel. Disclosed is also an image formed of at least a first region of diffractive flakes and a second region of non-diffractive flakes wherein the regions are adjacent one another and wherein one of the regions forms a logo, symbol or indicia that appears or disappears in dependence upon the angle of viewing.

Abstract: A novel method is disclosed wherein a reflective coated organic substrate is releasably coated with a thin film coating having one or more layers for forming flakes once removed from the reflective substrate. The reflective substrate is conveniently used to make glitter after the flake material is removed.

Abstract: Diffractive pigment flakes are selectively aligned to form an image. In one embodiment, flakes having a magnetic layer are shaped to facilitate alignment in a magnetic field. In another embodiment, the flakes include a magnetically discontinuous layer. In a particular embodiment, deposition of nickel on a diffraction grating pattern produces magnetic needles along the grating pattern that allow magnetic alignment of the resulting diffractive pigment flakes. Color scans of test samples of magnetically aligned flakes show high differentiation between illumination parallel and perpendicular to the direction of alignment of the magnetic diffractive pigment flakes. In another embodiment diffractive pigment flakes are selectively aligned by electrical fields. In other embodiments, special diffractive optical variable images are described and the method to produce them.

Abstract: Opaque glitter particles that are uniform in size and shape are disclosed that have an optically variable color with a change in angle of incident light. The glitter particles have an organic substrate and an optical interference structure on one or both sides of the organic substrate. The optical interference design can be a Fabry-Perot structure or can be an optically variable ink.

Abstract: A method and image made by the method is disclosed wherein non-spherical magnetically alignable optical pigment flakes in transparent carrier are applied to a substrate and are aligned by applying a magnetic field to the substrate. The pigment flakes align along magnetic field lines and a tool for impressing or scribing the flakes is applied to a sub-region of the substrate to realign or remove flakes from a desired region. For example a scribing tool can be used to scribe a signature or other marks within the magnetically aligned flakes. The flakes are then cured and the image is preserved which has optical and tactile features.

Abstract: A printed image is disclosed wherein the image may be in the form of an array of magnetically aligned platelets or flakes that may by uniform in shape and size and wherein the flakes are arranged in a particularly manner to form optically illusive images useful as security devices, or useful in beam steering applications. In one embodiment of this invention printed array is disclosed a plurality of concentric rings of magnetically aligned platelets disposed upon a substrate in the form of a Fresnel structure, preferably a Fresnel reflector. Advantageously, since the magnetic field can be controlled with respect to strength and direction, one can easily design a field that will correct for spherical aberration that would otherwise be present in a typical Fresnel reflector. In other embodiments of the invention optically illusive images of funnels, domes and cones are printed.

Abstract: A two-step method of making of a security printed image is disclosed and includes coating of the surface of a substrate with a predetermined image shape with an ink containing flaked magnetic pigment in a predetermined concentration, exposing a wet printed image to a magnetic field to align magnetic particles in a predetermined manner, allowing the ink to cure, and coating the substrate with a second printed image on the top of the first image. The second printed image with the same or different image shape is printed with another ink containing clear or dyed ink vehicle mixed with flaked magnetic pigment in a low concentration, exposed to the magnetic field of the same or different configuration as the first printed image and cured until the ink is dry.

Abstract: An optical structure is disclosed which includes a light transmissive substrate having a surface relief pattern applied thereon, such as a hologram. One or more layers can be patterned corresponding to materials playing the role of absorbers or reflectors on a Fabry-Perot type of optical structure. These materials are applied over portions of the surface relief pattern so as to form alphanumeric characters, bars codes, or pictorial or graphical designs. Additional layers may be applied to the patterned layer of the reflective or absorber materials and exposed portions of the surface relief pattern in order to provide desirable optical effects to the exposed portions of the surface relief pattern. In some embodiments, the optically active coating is a color shifting thin film, or contains color shifting flakes based on Fabry Perot designs.

Abstract: Opaque flakes, such as pigment or bright flake used in paints and inks, have a selected shape and/or other indicia to provide a covert security feature to an object. In some embodiments the composition includes base pigment, and the opaque covert flakes match the visual characteristics of the base pigment. In another embodiment, opaque covert flakes are mixed in the carrier with base pigment at a concentration sufficient to avoid changing the appearance of the composition. In another embodiment, opaque covert flakes are mixed in a clear or tinted varnish base that can be applied over an existing security feature. Shaped opaque covert flakes are not readily detectable by causal observation, but in some embodiments are easily seen at 50× magnification. In manufacturing the flakes a sheet of embossed frames are provided having symbols or indicia within; upon removing a coating from the sheet the coating material tends to break along frame lines and the resulting flakes are substantially uniform in size.

Abstract: Interference pigment flakes and foils are provided which have color shifting properties. The pigment flakes can have a symmetrical coating structure on opposing sides of a reflector layer, can have an asymmetrical coating structure with all of the layers on one side of the reflector layer, or can be formed with encapsulating coatings around a core reflector layer. The coating structure of the flakes and foils includes a reflector layer, a dielectric layer on the reflector layer, and a titanium-containing absorber layer on the dielectric layer. The pigment flakes and foils exhibit a discrete color shift so as to have a first color at a first angle of incident light or viewing and a second color different from the first color at a second angle of incident light or viewing. The pigment flakes can be interspersed into liquid media such as paints or inks to produce colorant compositions for subsequent application to objects or papers.

Abstract: Interference pigment flakes and foils are provided which have color shifting properties. The pigment flakes can have a symmetrical coating structure on opposing sides of a reflector layer, can have an asymmetrical coating structure with all of the layers on one side of the reflector layer, or can be formed with encapsulating coatings around a core reflector layer. The coating structure of the flakes and foils includes a reflector layer, a dielectric layer on the reflector layer, and a titanium-containing absorber layer on the dielectric layer. The pigment flakes and foils exhibit a discrete color shift so as to have a first color at a first angle of incident light or viewing and a second color different from the first color at a second angle of incident light or viewing. The pigment flakes can be interspersed into liquid media such as paints or inks to produce colorant compositions for subsequent application to objects or papers.

Abstract: Interference pigment flakes and foils are provided which have color shifting properties. The pigment flakes can have a symmetrical coating structure on opposing sides of a reflector layer, can have an asymmetrical coating structure with all of the layers on one side of the reflector layer, or can be formed with encapsulating coatings around a core reflector layer. The coating structure of the flakes and foils includes a reflector layer, a dielectric layer on the reflector layer, and a titanium-containing absorber layer on the dielectric layer. The pigment flakes and foils exhibit a discrete color shift so as to have a first color at a first angle of incident light or viewing and a second color different from the first color at a second angle of incident light or viewing. The pigment flakes can be interspersed into liquid media such as paints or inks to produce colorant compositions for subsequent application to objects or papers.

Abstract: The light transmitted and reflected by all-dielectric optically variable pigments varies according to viewing angle. The color travel of an all-dielectric optically variable pigment depends on amplitude changes and wavelength shifts in reflectance peaks of the pigment. The width and center wavelength of reflectance peaks can be controlled by selecting the ratio of thicknesses between high-index and low-index layers in a thin film stack. Reflectance peaks can regenerate or become suppressed and shift with tilt angle, thus providing a wide variety of color trajectories.

Abstract: Diffractive pigment flakes are selectively aligned to form an image. In one embodiment, flakes having a magnetic layer are shaped to facilitate alignment in a magnetic field. In another embodiment, the flakes include a magnetically discontinuous layer. In a particular embodiment, deposition of nickel on a diffraction grating pattern produces magnetic needles along the grating pattern that allow magnetic alignment of the resulting diffractive pigment flakes. Color scans of test samples of magnetically aligned flakes show high differentiation between illumination parallel and perpendicular to the direction of alignment of the magnetic diffractive pigment flakes.

Abstract: Diffractive pigment flakes are selectively aligned to form an image. In one embodiment, flakes having a magnetic layer are shaped to facilitate alignment in a magnetic field. In another embodiment, the flakes include a magnetically discontinuous layer. In a particular embodiment, deposition of nickel on a diffraction grating pattern produces magnetic needles along the grating pattern that allow magnetic alignment of the resulting diffractive pigment flakes. Color scans of test samples of magnetically aligned flakes show high differentiation between illumination parallel and perpendicular to the direction of alignment of the magnetic diffractive pigment flakes.

Abstract: Apparatus and related methods align magnetic flakes in a carrier, such as an ink vehicle or a paint vehicle to create optically variable images in a high-speed, linear printing operation. Images can provide security features on high-value documents, such as bank notes. Magnetic flakes in the ink are aligned using magnets in a linear printing operation. Selected orientation of the magnetic pigment flakes can achieve a variety of illusive optical effects that are useful for decorative or security applications.

Abstract: Covert flakes having one or more symbols and/or a selected shape are used in a composition, such as ink or paint, to provide a covert security feature to an object. In some embodiments the composition includes base pigment, and the covert flakes are covert pigment flakes that match the visual characteristics of the base pigment. In another embodiment, clear covert flakes are mixed in the carrier with base pigment. In another embodiment, clear covert flakes are mixed in a varnish base to provide a clear composition that can be applied over an existing security feature or elsewhere. The composition is used to print a field on the object, such as a stock certificate or bank note, for example. The covert flakes are not readily detectable by causal observation under visible light. In one embodiment, illuminating the covert security feature with ultraviolet light causes a covert flake to fluoresce and allows the observer to identify the location of the covert flake so that cover indicia may be observed.

Abstract: Interference pigment flakes and foils are provided which have color shifting properties. The pigment flakes can have a symmetrical coating structure on opposing sides of a reflector layer, can have an asymmetrical coating structure with all of the layers on one side of the reflector layer, or can be formed with encapsulating coatings around a core reflector layer. The coating structure of the flakes and foils includes a reflector layer, a dielectric layer on the reflector layer, and a titanium-containing absorber layer on the dielectric layer. The pigment flakes and foils exhibit a discrete color shift so as to have a first color at a first angle of incident light or viewing and a second color different from the first color at a second angle of incident light or viewing. The pigment flakes can be interspersed into liquid media such as paints or inks to produce colorant compositions for subsequent application to objects or papers.

Abstract: Multilayer chromatic diffractive pigment flakes and foils are provided having diffractive structures thereon. The diffractive pigment flakes can have a symmetrical stacked coating structure on opposing sides of a reflective core layer, an asymmetrical stacked coating structure on one side of a reflective layer, or can be formed with one or more encapsulating coatings around the reflective core layer. The diffractive pigment flakes can be interspersed into liquid media such as paints or inks to produce diffractive compositions for subsequent application to a variety of objects. The foils can be laminated to various objects or can be formed on a carrier substrate. The diffractive pigment flakes and foils can be formed with a variety of diffractive structures thereon to produce selected optical effects.

Abstract: All-dielectric diffractive pigment flakes can be applied to an object to impart a diffractive effect to the object without substantially changing the background color of the object. In one case, such diffractive pigment flakes can be applied to a white object to impart a white diffractive effect. The thickness of the dielectric layers in the diffractive pigment flakes can be chosen to provide thin-film interference, as well as diffraction from the interfaces between layers patterned with a diffraction grating. In some cases, the thin-film interference can provide color shifting in addition to the diffractive effect.