High-fire pottery… cone 8-10… where skill, clay, glaze and fire combine to produce the most stunning works of ceramic art. Different methods of firing to reach these temperatures change the final appearance of both clay and glaze. These clay samples are shown fired in both oxidation (electric, tile on right) and reduction (fueled, tile on left) atmospheres. Highfire clays are considered foodsafe, even when unglazed, when fired to their full maturity at cone 8-10.