Americas Premier Clay Maker. Moist clay manufacturing at Sheffield Pottery has set a new standard in the ceramic industry. Their Premium clay bodies are available screened and iron filtered. Stock formulas range from low-fire earthenware clay to the finest cone 10 stoneware and porcelain. They also make custom clay bodies and casting slips to your exact specifications using our state of the art facility. Sheffield Pottery is your complete Ceramics Supply Store. They have everything you need for your pottery studio or classroom at great discounted prices and many are available with free shipping. Buy with confidence as continue beyond our 70th Anniversary.