<P> Oil - based clays are made from various combinations of oils, waxes, and clay minerals . Because the oils do not evaporate like water, oil - based clays remain malleable even when left in dry environments for long periods . Articles made from oil - based clays cannot be fired, and thus are not ceramics . Because rising temperature decreases oil viscosity, the malleability is influenced by heating or cooling the clay . Oil - based clay is not water - soluble . As it can be re-used, it is a popular material for animation artists who need to bend and move their models . It is available in a multitude of colors and is non-toxic . </P> <P> Oil - based clays are referred to by a number of genericized trademarks . Plastilin (or Plasteline), which was patented in Germany by Franz Kolb in 1880, was developed by Claude Chavant in 1892 and trademarked in 1927 . Plasticine was invented in 1897 by William Harbutt of Bathampton, England . Plastilina is trademarked as Roma Plastilina by Sculpture House, Inc . According to their website, their formula is 100 years old . Roma Plastilina contains sulfur, and since certain moldmaking compounds do not set in sulfur's presence, making molds of items made of industrial plasticine is difficult . </P> <P> Readily worked in fine detail, oil - based clays are also suitable for the creation of detailed sculptures from which molds can be made . Castings and reproductions can then be produced from much more durable materials . Cars and airplanes may be created using industrial design - grade modelling clay . </P> <P> Polymer clay is a modelling material that cures when heated from 265 ° F (129 ° C) to 275 ° F (135 ° C) for 15 minutes per ⁄ inch (6.4 mm) of thickness, and does not significantly shrink or change shape during the process . Despite being called "clay", it generally contains no clay minerals . Polymer clay is sold in craft, hobby, and art stores, and is used by artists, hobbyists, and children . Polymer clay is also popular in animation, since it allows static forms to be manipulated frame after frame . Leading brands of polymer clay include Fimo, Kato Polyclay, Sculpey, and Modello . </P>

Sculpture that is modeled in clay or wax