Paper clay (sometimes referred to as fiberclay) is any clay body to which processed cellulose fiber (paper being the most common) has been added. Earthenware, terra cotta, stoneware, porcelain and bone china clay bodies can be made into paper clay. The more fiber added to the clay body, the stronger the unfired dry paper clay, but the weaker the fired body. The less fiber added to the clay body, the weaker the unfired dry paper clay, but the stronger the fired body.