Exploring Pottery: Clay Basics and Techniques

1. Intro to Pottery

2. 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)

3. 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.

4. 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.

5. 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

6. 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.

7. Pinch method: making potteryby 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.

8. 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.

9. 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!)

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

11. Types of Clay • Porcelain • Stoneware • Earthenware

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

14. 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)

15. 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

16. 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

17. 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.