EARTHENWARE - Clay that has been fired to become bisque.
Earthenware: is a ceramic material, clay that has been fired to become bisque and used for decorative and practical work. The formulation of clay bodies differs depending on the source and in the past, pottery businesses grew up round places where good quality clay could be found. In those days, one factory did everything from digging up the clay to selling the finished pieces. The composition of clay is 25% ball clay, 28% kaolin, 32% quartz, and 15% feldspar. The most common clay is red clay that can be fired between 600º C and 1100º C. At 600º C, it becomes solid, unpliable, but it should be fired to a higher temperature to stop it shrinking and to make it stronger. The firing changes it into a solid, breakable but still porous material which is called bisque. White and buff colored earthenware clays are available. Earthenware is not as strong and more porous than stoneware, but it is cheaper and easier to work with. It’s used industrially for many products such as bricks, flower jars, etc ., and when glazed, it is no longer porous and is used for domestic ware.