Permoplast Modeling clay is a plastic medium with many uses in every grade of school, from kindergarden and primary grades through high school. At the adult level it is equally useful to clay animators, stylists and hobbyists. For over eighty years Permoplast has been the standard school quality non-hardening modeling clay. The trade name Permoplast means permanently plastic. This clean, sanitary modeling clay can be used over and over. Permoplast packages bear the AP seal certifying that this clay contains only pure, harmless ingredients and non-toxic colors.