A method of providing a configuration of a system of interference filters with a visible color shifting effect, includes: a hue matching step of identifying a configuration of a first interference filter including two first metal layers and a first spacer layer therebetween, and a configuration of a second interference filter including two second metal layers and a second spacer layer therebetween, wherein the first and second filters match in hue at the first viewing angle, and the mismatch in hue at the second angle; and a lightness adjustment step which may include modifying the layer material or the layer thickness of one of the metal layers; wherein a difference in lightness at the first viewing angle between the first and second modified filters is less that a difference in lightness at the first viewing angle between the first and second filters.

Materials for use in 3D printing comprising a color shift pigment that change colors when viewed at different angles. More specifically, the materials comprise a color shift pigment being a silicon oxide core with metal oxide shell disposed thereon and a polymeric component.

A method of providing a configuration of a system of interference filters with a visible color shifting effect, includes: a hue matching step of identifying a configuration of a first interference filter including two first metal layers and a first spacer layer therebetween, and a configuration of a second interference filter including two second metal layers and a second spacer layer therebetween, wherein the first and second filters match in hue at the first viewing angle, and the mismatch in hue at the second angle; and a lightness adjustment step which may include modifying the layer material or the layer thickness of one of the metal layers; wherein a difference in lightness at the first viewing angle between the first and second modified filters is less that a difference in lightness at the first viewing angle between the first and second filters.

A plastics material component for an aircraft includes (i) a substrate, which comprises one or more thermosetting plastics materials, and (ii) one or more layers which are applied to the substrate, at least one layer S1 comprising mica. A method for producing the plastics material component includes providing a substrate including at least one thermosetting plastics material or one polymer which is crosslinked to form a thermosetting plastics material, and applying one or more layers to the substrate, wherein at least one layer includes mica. The mica-containing layer is applied directly to the substrate and the application is carried out before and/or during the curing of the thermosetting plastics material.

The invention provides a method for producing a 3D item (1) by means of fused deposition modelling, the method comprising a 3D printing stage, wherein the 3D printing stage comprises a reflective material deposition stage, wherein the reflective material deposition stage comprises: (A) providing 3D printable material (201) comprising (i) a polymeric matrix material (211) that is transmissive for UV radiation, especially wherein the polymeric matrix material (211) comprises thermoplastic material, and (ii) a reflective material (212) that is reflective for the UV radiation and that is at least partly enclosed by the polymeric matrix material (211); wherein the reflective material (212) comprises a first fluoropolymer; and (B) depositing the 3D printable material (201), to provide the 3D item (1) comprising 3D printed material (202) comprising the matrix material (211) and the reflective material (212).

Apparatus and method to authenticate 3D printer consumables are described herein. An example 3D printer includes a consumable used by the three-dimensional printer to print a three-dimensional object, the consumable containing embedded ceramic particles, the ceramic particles having luminescent properties such that they emit light having a first wavelength when they are illuminated by light having a second wavelength, and a detector to detect the presence of the ceramic particles in the consumable.

Materials for use in 3D printing comprising a color shift pigment that change colors when viewed at different angles. More specifically, the materials comprise a color shift pigment being a silicon oxide core with metal oxide shell disposed thereon and a polymeric component.

The invention provides a method for 3D printing a 3D item, the method includes, providing a filament of 3D printable material and printing said 3D printable material, to provide said reflector comprising 3D printed material, wherein the 3D printable material comprises particles, wherein the particles comprise one or more of glass and mica, wherein the particles have a coating of one or more of a metal coating and a metal oxide coating, and wherein the particles have a longest dimension (A1) having an longest dimension length (L1) selected from the range of 10 m-2 mm, and the particles have an aspect ratio of at least 10, wherein the coating comprises a light reflective material and the 3D printable material comprises a polymeric material which is transparent to light to enable the particles to provide a diffuse reflection having a reflectivity of at least 85%.