Polymer Clay, sold under the brand names of FIMO, Sculpey, Kato Polyclay, Pro-Sculpt and others is a plastic-based material composed of polyvinyl chloride particles. Unlike traditional earth clays, polymer clay comes in a variety of colors that can stand alone or be easily blended.
Polymer clay does not dry out, and can be used indefinately if properly stored. The biggest distinction between polymer clay and earth clay is the way the clay is cured. Polymer clay does not need the high temperatures required for firing, and instead can be baked in a home oven.