Ceramics/Pottery

1. Ceramics/Pottery Unit 2 – Terminology

2. Basic Construction • Pinch – an ancient method of producing pottery, achieved by placing the thumb into a ball of clay, and using it and the fingers to pinch the opening larger, and walls thinner. • Slab – a method of rolling clay into sheets, to be used in box, cylinder or free-form construction. • Coil – an ancient method of forming pots and sculpture, achieved by rolling clay into ropes, and using them as construction elements. The coils may remain, or be smoothed. • Throwing – the term used for creating pots on the wheel. • Centering – the first step in forming a wheel thrown piece, where the clay is compressed on the spinning wheel until it rotates with no variation or wobble.

3. Basic Construction Continued • Trimming – the method of cutting excess clay away from wheel thrown pots, usually in the leather-hard state, to refine the from and to eliminate excess weight. • Template – a shaped surface usually made of wood or bisque fired clay, which can be pressed into a number of clay forms in order to create matching elements. • Slip and Score– the method of attaching pieces of clay together, achieved by scratching the surfaces to be joined, and wedding them with either water or slip. (slip and score)

4. Tools and Equipment Kiln – A thermally insulated chamber, or oven, in which a controlled temperature regime is produced. Kilns are an essential part of the manufacture of all ceramics, which, by definition, require heat treatment, often at high temperature. During this process, chemical and physical reactions occur which cause the material to be permanently altered. Pug Mill – a fast continuous mixer used for recycling clay. Wire clay cutter – a wire or string with toggles at the end used to cut clay Sponges – used to hydrate the clay and smooth the clay surface Needle/Pin Tool– used for cutting, scoring, and marking the surface of clay Fettling Knife – has a long, narrow, pointed blade to make cutting wet clay easier

5. Tools and Equipment Continued Ribs – used for shaping and smoothing Banding wheel – used for hand building; it rotates and allows one to work on pieces from all angles Wire loop tools – comes in assorted sizes and are used to remove clay Ware boards – used to store work in progress and are made of hard wood; the porosity of the wood helps absorb moisture from the clay and prevents it from sticking to the board. Modeling Tools– used to create smooth edges, or curves on items to be modeled. Calipers – used to measure the width of a pot for making lids or joining two pieces.

6. Tools and Equipment Continued Bats - removable discs that fit on the wheel head on which pots are thrown, which are essential for preventing warping. Slab roller – Has two rollers and a tabletop through which clay is fed, sandwiched in canvas, and rolled to a desired uniform thickness Canvas – used to cover the table so clay won’t stick when rolling out Dowel Sticks – Used to help roll out a slab that is an even thickness

7. Glazing • Glazing–the act of applying glaze or underglaze to a bisque-fired ceramic piece, for the purpose of both sealing and decorating the piece. A clear or translucent glaze will reveal the clay or design underneath, and opaque will not. • Types of Glaze: • Glaze – A fired glasslike coating that seals, and usually colors, ceramic pieces. Or to apply glaze to a bisque fired piece. • Underglaze – A ceramic paint, without glaze components, used to detail on unfired, or sometimes fired clay. Or to apply underglaze to a piece. • Underglazing– the act of apply underglaze usually to an unfired, leather-hard piece, in order to create a detailed design or to prepare it for combing or sgraffito.

8. Glazing Continued Clear Glaze– Completely see-through glaze that create a shiny seal/coat. Translucent – A colored glaze that is partially see-through. Sea Mist Green is an example of a translucent glaze. Opaque – A solid color that light is unable to penetrate. Black, Lakspur and Tawny Birch are examples of opaque glazes. Consistency – The quality of a glaze or underglaze that makes it suitable for smooth application. Also, to have an even quality throughout. Banding– Applying rings of color to a wheel-thrown piece, usually using a kick or banding wheel. Trailing – Applying a controlled flow of slip, glaze, or underglaze to a piece as a method of design. Dry Foot – Keeping the contact area of a piece, glaze-free to keep it from sticking to the kiln shelf during firing. A wax resist can be used for this. Food Safety – All food-bearing surfaces are glazed and only glazes certified as food-safe are used, to prevent food from absorbing chemicals.

9. Decorating Carving – Removing clay from a surface as a method of drawing or texturing a piece. Carving usually results in a low-relief design. Stamping– Pressing a textured tool into clay, usually to create a pattern. The stamp may be made and bisque fired by the artist, or it may be an item that generally has another use, such as a magic marker or spoon handle. Sprigging– Pressing clay into a shallow mold, then removing the molded detail and apply to a piece. Commercially made ceramic, such as Wedgwood ware, make use of the sprigging process.

10. Decorating Continued Burnishing – Polishing leather-hard clay to create a shiny surface, using a shell, stone or the bowl of a spoon. While used now primarily as a decorating technique, ancient cultures used burnishing to increase the water-holding abilities to unglazed ware. Incising – Using a sharp tool to draw a linear image or design into the surface of soft or leather-hard clay. The incising may later be enhanced by rubbing color into the design. Sgraffito – A type of incising, where color, usually underglaze, is a applied to leather-hard clay, and a sharp tool is used through the color to reveal the clay underneath. Success of the process usually depends upon contract between the color and the clay.