AbstractMost of us who are involved with color in the plastics industry think of pigments and dyes incorporated into or coated onto a polymer in order to produce asthetic appeal. But unusual colored effects can be created through selective embossings. This article discusses the history of diffraction gratings, how and why they work, how they are made, and how this technology can be applied to the plastics industry to create unique visual effects. Examples are given of design variations which are possible using a basic 1–in. circular diffraction grating. Also included are examples of end‐use applicati