Plastic arts are art forms which involve physical manipulation of a plastic medium by moulding or modeling such as sculpture or ceramics. The term has also been applied more broadly to all the visual (non-literary, non-musical) arts. Materials for use in the plastic arts, in the narrower definition, include those that can be carved or shaped, such as stone or wood, concrete or metal. "Plastics" meaning certain synthetic organic resins have been used ever since they were invented, but the term "plastic arts" long preceded them. The term should not be confused with Piet Mondrian's concept of "Neoplasticism."