In this thesaurus, the term 'clay' refers to the raw material. If deliberately heated, whether in a fire or a kiln, etc. but not sun dried, the Preferred term in Materials is ‘fired clay’, with ‘baked clay’ a Non-Preferred Term, as it was frequently used historically. No Technique term is entered. N.B. In the Department of Ancient Egypt and Sudan, the Materials terms ‘mud’ and ‘clay’ have been used interchangeably for unfired objects such as bricks. figurines, and vessels.
http://collection.britishmuseum.org/id/thesauri/x11519, http://collection.britishmuseum.org/id/thesauri/x11751, http://collection.britishmuseum.org/id/thesauri/x10705, http://collection.britishmuseum.org/id/thesauri/x10591, http://collection.britishmuseum.org/id/thesauri/x11496, http://collection.britishmuseum.org/id/thesauri/x11697