<Table> <Tr> <Td> </Td> <Td> This article does not cite any sources . Please help improve this article by adding citations to reliable sources . Unsourced material may be challenged and removed . (December 2009) (Learn how and when to remove this template message) </Td> </Tr> </Table> <Tr> <Td> </Td> <Td> This article does not cite any sources . Please help improve this article by adding citations to reliable sources . Unsourced material may be challenged and removed . (December 2009) (Learn how and when to remove this template message) </Td> </Tr> <P> Industrial plasticine is a modeling material which is mainly used by automotive design studios . It was developed as an industrial version of plasticine or hobby clay . </P> <P> Industrial plasticine is based on wax and typically contains sulfur, which gives a characteristic smell to most artificial clays . The styled object can be used to create moulds . However, largely because sulfur interfered with some mould - making processes, especially if clay surfaces are unsealed surfaces and platinum - cure Room Temperature Vulcanization silicone was used, sulfur - free variants are now available; these are usually much lighter than sulfur - containing clays . </P>

What kind of clay do car designers use