The medium

The Clay
In Germany, in the late 1930s, an enterprising woman named Fifi Rehbinder developed and marketed a clay product, which she called Fifi Mosaik, to use for doll heads. In 1964 she sold the formula to Eberhard Faber who developed it into the Fimo we know today.
Polymer clay is a pliable, blendable polymer compound for artists and crafters. It's not a true earth clay - clay is fine particles of silicate suspended in water, whereas polymer clay is fine particles of polyvinyl chloride (PVC) suspended in plasticizer - but it can be used much like clay.