Clay differs from the inelastic earths and fine sand because of its ability, when wet with proper amount of water, to form a cohesive mass and to retain its shape when molded. This quality is known as plasticity. When heated to high temperatures, it also partially melts, resulting in the tight, hard rock-like substance known as ceramic. A typical clay body usually consists of china clay, ball clay (added to increase workability and plasticity), potash feldspar, silica and than clay. These are available in the market, ready to use. The most common types of clay are earthenware, stoneware and porcelain.
Wedging the clay is the primary and most important step of pot-making. It is done before any other activity to help compact the clay and get air pockets out, ensuring that it is uniform in stiffness. If the clay body isn’t wedged properly, the chances are one won’t get the pot right. Quite interestingly, on the contrary, if the body is wedged well, throwing will be almost effortless.