CeramicsPottery Course 8115 BASICS of CLAY Clay is

Ceramics-Pottery Course 8115 BASICS of CLAY

Clay is… a variety of earthy Materials formed by broken down rock. (granite) OR particles of decomposed rock combined with water to create a plastic, malleable body which is then fired in a kiln to fuse the particles back into a stone-like state.

STAGES OF CLAY… 1. Workable: Soft, Plastic, Sculptable 2. Leather Hard: No longer workable. Dry enough to support it’s own weight 3. Bone Dry: Completely Dry, chalky coloring and no longer cold but room temperature. Very Fragile. Greenware refers to any unfired clay. 4. Bisqueware: Clay fired once. Whiter in color and very Fragile. 5. Glazeware: Clay fired twice after glaze applied. Sometimes shiny. Fragile but also sturdy.

OTHER TERMS: Knead: working clay with the palms of your hands to remove air bubbles and form consistency. Slip: Watered Down clay used similar to glue. Score: A method of making small crosshatch marks (#) in clay to rough an area in order to attach two pieces together. Glaze: mixture of powdered ceramic materials that when fired becomes a glass like coat. Glaze is used to decorate, protect and make the ware food-safe. Kiln: an oven for firing ceramics. 1500 degrees.

METHODS OF WORKING CLAY Coil : A building technique utilizing long "ropes" of clay stacked in layers upon one another to create a form. (Snakes) Pinch: The process of starting with a ball of clay, inserting your thumb and "pinching" the clay between your thumb and fingers. Slab: Using thin sheets of clay to build a structure, the sheets can be either rolled or stretched out. Mold: A form used for support and shaping of the clay, usually made of paper, clay or plaster. Soft slabs are draped on top or slumped inside and allowed to get leatherhard and then built upon or cut and shaped further. Thrown: making pots on a quickly rotating wheel.