Particles are encapsulated with a layer or sequence of layers. The particles can be flakes and the layers can form an optical interference stack for use as an optically variable pigment, among other purposes. In a particular embodiment a highly reflective metal layer is deposited around a glass flake...http://www.google.com.hk/patents/US6777085?utm_source=gb-gplus-share專利 US6777085 - Article and method of preparing pigments using multiple deposition sources
