Retroreflective colorants

Abstract

A reflective material comprising a multilayered array of particles encapsulated by a matrix material, the reflective material defining a primary surface, the reflective material exhibiting: (i) visible retroreflection of incident radiation, wherein a wavelength of visible retroreflected radiation decreases from a first visible wavelength at a first angle to the primary surface to a second, shorter wavelength of visible retroreflected radiation as the viewing angle to the primary surface increases; and (ii) Bragg diffraction of the incident radiation, wherein the wavelength of radiation Bragg diffracted normal to the primary surface is longer than the wavelength of visible radiation, such that no visible radiation is retroreflected or Bragg diffracted in a direction normal to the primary surface.

Dependencies are inferred from the claim text.