Intro to Pottery

Clay! Abundant natural material Found all around us, but requires extra processing before being put to use Just about the coolest art material…ever (FACT)

History/Background Pottery shards offer insight into the history of humankind- historical development, cultural values, and social expression. Throughout history clay has contributed to human comfort or technology ie. Water pipes, fired bricks for architecture, floor and wall decoration, vessels for food and drink as well as heat-resistant tiles on space shuttles.

Vocabulary Appendage: an added part, ie. Spout, handle Body: the inner or essential part of the ware Foot: the base of any ceramic item Firing: applying heat to ware Kiln: a furnace or oven used for firing ware (many types) Plasticity: the characteristic of clay that allows it to be stretched.

Kiln Wash: a solution that is used to cover shelves and the inside of the kiln to prevent the sticking of the ware to the surface supporting it Matt: a dull surface with no gloss Opaque: not transparent or translucent. Does not allow light to shine through Transparent (glaze): a clear glaze that shows underglazes or clay color through

Stilts: a three-pronged support for glazed ware in the kiln. Wedging: kneading clay to remove air bubbles and to develop a uniform texture. Score: to carve crosshatch lines into clay to aid in joining pieces together. Slip: clay to which enough water has been added to make a creamy liquid. Used as glue, decoration and slip casting.

Pinch method: making pottery by pressing, pulling, rolling, and pinching a ball of clay. Slab Method: making pottery by rolling flat sheets of clay, cutting and joining. Coil Method: making pottery in which ropes of clay are wound to form spirals or rings to be stacked or joined. Wheel: used for throwing clay into a cylinder form.

Glaze: a glass-like coating applied to clay which is fired to produce a hard, shiny or matt finish. Greenware: ware that has not been fired. Grog: hard fired clay that is crushed or ground and added back into clay for strength, stability, and to decrease shrinkage. Needed in clay for hand-building.

Dermatitis Inflamation of the skin due to exposure to an irritant. Like an allergy, there is no cure. Only solution is to stop using clay (oh the horror!)

Silicosis A lung disease Acquired through prolonged inhalation of silica dust (clay, glaze) An irreversible condition with no cure

Types of Clay Porcelain Stoneware Earthenware

Porcelain White firing, smooth, vitreous (glassy) clay Translucent if worked to a thin wall Highest firing temperatures temperatures (2264º F and higher)

Stoneware Name comes from the dense, hard character of the clay body. Color includes off-white, tan, gray, and brown Impervious to water when fired to maturity Second highest firing clay body (2100º and above)

Earthenware Abundant, available in nearly every part of the world. Color is generally red, orange, buff (skin color), yellow and brown. Low firing and porous. Terra cotta is one example (tiles and flowerpots) Terra Cotta Army: Forbidden City, Beijing

5 Stages of Clay Wet: the stage in which you build with your clay Leatherhard: no longer very pliable, cold to the touch, fingers no longer leave imprints. Last stage to add attachments. Best stage to carve details. Bone Dry/Greenware: if held to skin no longer feels cold. The driest it will be without firing. MOST FRAGILE!! Cannot be fixed if broken in this stage Bisque Fired: ware that has been fired once. Has a high pitched “ping” to it, slightly pink in color Glaze Fired: Finished glazed work

Drying… sooo important As clay dries it loses water, becomes stiffer, shrinkage begins. Wrap all work tightly in soft plastic Plastic slows down but does not stop the drying process. Write your name on the plastic Do not ever lift the plastic of someone else’s project.