Ceramic Terms to Know Name______________________ Building Techniques: This term refers to several techniques of building pots using your hands and simple tools rather than the potter’s wheel. 1. Pinch- In ceramics this method of shaping clay starts with a smooth ball and opening a hole with your thumb. The form is then shaped by pinching and turning the ball in your hand. 2. Slab- In ceramics this method starts with flat slabs cut to shape and join together using scoring and wet clay call slip. Note, large forms are difficult because of stresses on the seams and because the slab naturally sags. 3. Coil- One of the oldest ways of forming pottery. Long strands of clay which are laid on top of each other and joined through blending coil to coil. Coil pieces can be almost any shape or size. 4. Wheel thrown- The term throw comes from Old English meaning spin. A piece of clay is placed on a potter’s wheel head which spins. The clay is shaped by compression while it is in motion. Often the potter will use several thrown shapes together for on piece (a teapot can be constructed from three or four thrown forms). Stages of Clay: Clays form changes throughout the building process. Different techniques can be done to the clay but only at the right stage. 1. Plastic stage- this is when clay is easily manipulated and can bend. This is the stage we use to build our piece. 2. Leather hard- this is when the clay damp enough to carve into but to firm to bend and create a piece. 3. Bone dry stage/Greenware- this is when there is no visible moisture, no dampness to touch and clay is ready to be fired. 4. Bisque- this is when clay has been fired once and is ready to be glazed. Types of Clay: There are different types of clay. One type might be better for wheel throwing while another type is better used for hand building. The different types of clay also get fired in the kiln at different temperatures. 1. Earthenware- A low-fire clay. Porous and not waterproof. To be functional, it must be glazed. 2. Terra cotta/Red clay- A brownish-orange earthenware clay body commonly used for ceramic sculpture. 3. Stoneware- A high-fire clay. Stoneware is waterproof even without glaze; the resulting ware is sturdier than earthenware. 4. Porcelain- True porcelain was being made in China and Korea around 960 A.D. Porcelain is a combination of kaolin (a pure, white, primary clay) silica and feldspar. A unique aspect of porcelain is that it can be worked as clay, but when fired properly reaches a state similar to glass. Primary qualities of porcelain are translucency and whiteness. Coloring and Decorating Clay: There are many ways to decorate clay. These are a few way we will be experimenting with decorating our pieces. 1. 2. 3. 4. 5. 6. 7. Glaze- A coating of material applied to ceramics before firing that forms a glass-like surface. Glazes can be colored, opaque, translucent or matte. Matte Glaze- Dull-surfaced glazes, lusterless and non shinny. Crackle glaze- Minute decorative cracks in the glaze that are often accentuated by rubbed-in material. Sgraffito- this comes from the Italian word meaning “scratched through” and is done by incising or cutting a design through a colored slip coating to reveal the clay body. Wax Resist- In this decorative technique, patterns or designs are created by brushing wax medium over an area of clay, slip, or glaze to resist the final glaze application when the wax is dry. Slip Trailing- this is another decoration method. Slip (a liquid clay) is applied to the greenware through a tube or nozzle, much like icing a cake. Stamping- this is the technique of pressing forms into the clay to get decorative effects. Parts of a Vase: There are four main parts of a vase. The parts of a vase correspond to the parts of a human body. 1. Mouth- the opening at the top of a vase. 2. Neck- the narrower part that leads from the body of the vase to the mouth. 3. Body- the main part of the vase. It is usually the largest part. 4. Foot- the part of the vase that meets the floor. Remember: Clay shrinks and dries at different rates. The thinner layer will dry before the thinker layer. The thinner layer will shrink faster than the thicker layer causing cracking. If parts are attached you need to slip and score to help hold things together.