ΒΆ Ceramic and Pottery Glossary of Terms
Original Post: https://www.oberk.com/Ceramic-and-Pottery-Glossary-of-Terms
- Absorbency: The ability of a clay body to absorb water, impacting the drying and firing processes
- Alumina: A major component of clay used in ceramics that enhances stability and increases the firing temperature
- Ball Clay: A highly plastic variety of clay that adds workability and increases strength, used in ceramic formulas
- Bat: A flat disc made from wood, plastic, or plaster that attaches to a potter's wheel for throwing pottery
- Bat Pins: Pins used to secure a bat to the potter's wheel, ensuring stability during throwing
- Bentonite: A type of clay that increases plasticity and strength in a clay mixture
- Bisque: Pottery that has been fired once but not yet glazed
- Black Core: A defect in fired clay where the center remains black due to incomplete oxidation of carbon within the clay
- Blackhard: A stage in drying clay where it has stiffened but is still slightly moist, prior to bisque firing
- Bone China: A type of porcelain that includes bone ash for added strength and whiteness
- Bone Dry: The condition of clay that is completely dry and ready for bisque firing
- Burnishing: Polishing the surface of leather-hard clay to compact it and produce a smooth, shiny surface
- Candling: A slow, low-temperature pre-firing that ensures even drying and prevents defects
- Casting Slip: A liquid clay used in slip casting, a technique for shaping pottery by pouring slip into molds
- Ceramic Change: Permanent chemical and physical changes that occur in clay and glazes when fired
- Ceramics: Objects made from clay that are subject to a firing process
- Chamois: A type of soft leather used to smooth and compress the rims of wheel-thrown pottery
- Cheesehard: Clay that is firm and moist, ideal for carving or sculpting
- China Clay: A pure form of clay favored for its whiteness and used in the production of porcelain; also known as kaolin
- Chuck: A clay form used to hold pots upside down for trimming on a potter's wheel
- Clay: A naturally occurring inorganic material made up of "plate-like" particles that is plastic when wet. It is used to make ceramics.
- Clay Body: A mixture or formula of types of clay, minerals, and other additives that is used for pottery
- Coiling: A hand-building technique favored for decorative ceramics in which clay is rolled into long strings or strands and coiled to construct pottery
- Cones: Pieces of ceramic material used to visually indicate the temperature inside of a kiln. The cones melt at specific temperatures, showing when the ceramics in the kiln have been exposed to the right amount of heat.
- Contraction: Non-reversible shrinkage of the clay during drying and firing
- Crackle glaze: A decorative glaze that intentionally cracks during cooling to form a cracked pattern
- Crawling: A defect caused by uneven glazing or over-glazing where the glaze retracts from the clay during firing, exposing bare clay
- Crazing: Fine cracks that appear in the glaze of ceramic wares due to tension between the clay and glaze
- Dipping: Immersing pottery in a fluid glaze or slip
- Dunting: Cracking that occurs in ceramic pieces during cooling due to thermal stress
- Earthenware: A type of clay pottery that has been fired at relatively low temperatures and is porous until glazed
- Enamel/On-Glaze Decoration: A type of colorful decorative coating applied to ceramics, often glass-like in appearance
- Firing: The process of heating clay or glaze to specific temperatures in a kiln to achieve a permanent hard state
- Flameware: A type of clay body that can withstand direct heat, used for making cooking pots
- Frit: A combination of glaze materials made by melting, cooling, and grinding glaze into a powder to then be used as part of a glaze formula
- Glaze: A glassy coating made of a variety of materials and colorants that are ground and mixed with water, then applied to pottery to seal and decorate the surface
- Glaze Fit: The compatibility of a glaze with a clay body
- Greenware: Pottery that is going through the drying process and has not yet been fired
- Grog: Fired clay that has been ground into particles that are then added to a clay body to reduce its shrinkage and improve its thermal shock resistance
- Hand-Building: The process of forming pottery using only your hands and simple tools rather than a wheel
- High-Temp Glaze: Glaze that is formulated to mature at temperatures above 2,200 degrees F. These glazes are durable and popular in the making of stoneware and porcelain.
- Intermediate Glaze: Glaze that matures at mid-range temperatures, around 1,900 to 2,200 degrees F, and produces more vibrant colors than high-temp glazes
- Iron Oxide: A common coloring agent used in clays and glazes to create red, yellow, or black hues
- Kaolin/China Clay: A fine, pure white clay used in making high-quality porcelain
- Kidney: A kidney-shaped rubber, wooden, or metal tool used to smooth and shape clay
- Kiln: A furnace or oven built specifically for firing clay and glazes
- Kilnwash: A protective coating applied to kiln shelves to prevent sticking from glazes
- Kintsugi/Kintsukuroi: The Japanese art of repairing broken pottery with lacquer dusted or mixed with powdered gold, silver, or platinum
- Leatherhard: A stage of drying during which clay is still damp enough to be joined or carved but holds its shape. Artists must work quickly during this very short drying stage.
- Low Mid-Range: Ceramic processes that fire to temperatures between earthenware and stoneware
- Low-Temp Glaze: Glaze designed to mature at lower temperatures, around 1,900 degrees F or lower
- Lusters: Metallic glazes that give a shiny, iridescent finish to ceramics
- Maiolica: A type of lead-glazed earthenware characterized by a white surface with brightly colored decoration
- Maturing Temperature: The temperature at which a clay body or glaze reaches its optimum level of strength and solidity
- Ovenware: Pottery formulated to withstand the thermal shocks of oven use
- Oxidation: A firing atmosphere with ample oxygen, allowing for bright, vivid glaze colors
- Paper Clay: Clay mixed with cellulose fibers to enhance strength and reduce shrinkage
- Pinching: A hand-building technique involving squeezing the clay between the fingers and thumb
- Pinholes: Small holes in the fired glaze surface caused by escaping gases during firing
- Plasticity: The quality of clay that allows it to be shaped and to retain its shape
- Porcelain: A high-fired, glass-like ceramic material known for its strength and translucence
- Porosity: The measure of the empty spaces in a material, which affects the clay's absorbency
- Potter's Wheel: A machine used in the shaping (throwing) of round ceramics
- Pottery: General term for pots and other articles made from fired clay
- Production Pottery: Pottery items produced in large quantities
- Pug Mill: A machine used to mix and condition clay
- Pyrometer: A device used to measure high temperatures in a kiln
- Raku: A Japanese pottery firing process that involves removing the piece from the kiln while hot and allowing it to cool in the open air or in combustible materials
- Reduction: A firing atmosphere with reduced oxygen, often producing rich, earthy glaze colors
- Rib Tool: A flat, rigid tool used to shape, smooth, or scrape clay
- Sagger: A ceramic container used to protect or support delicate pottery during firing
- Salt Glaze: A glaze formed by introducing salt into a kiln at high temperatures, which vaporizes and forms a glassy coating
- Sgraffito: A technique of applying layers of color to leatherhard pottery and then scratching off parts to create contrasting patterns
- Shrinkage: The reduction in size of a clay body due to water loss during drying and firing
- Sieve: A mesh tool used to strain clays and glazes to remove lumps
- Slab: A flat piece of clay that is rolled out and used in hand-building techniques
- Slab Roller: A mechanical device used to roll out uniform slabs of clay
- Slip: Liquid clay used in decoration or as a bonding agent between pieces of clay
- Slip Casting: A technique for forming pottery by pouring slip into a plaster mold
- Slump Mold: A form used to support clay in a specific shape during slab construction
- Slurry: A thick, creamy mixture of clay and water used in joining clay pieces and for surface decoration
- Soaking: A period at the end of a kiln firing where the temperature is held to even out heat and complete the maturation of glazes
- Stain: Colored oxides and other compounds used to color clay bodies and glazes
- Stilt: A tripod or support used to hold pottery during firing to prevent it from sticking to the kiln shelves
- Stoneware: A type of clay body fired to a high temperature that is very strong and dense
- Tenmoku: A type of Japanese glaze that is thick, glossy, and dark, typically ranging from black to dark brown, often used in tea ware
- Tensile Strength: The resistance of a material to breaking under tension
- Thermal Shock: The stress a material undergoes when it experiences sudden changes in temperature
- Throwing: The process of shaping pottery on a potter's wheel
- Underglaze: Colored decoration applied on unfired clay that can be coated with a transparent glaze
- Vitrification: The process of firing pottery to the point where it becomes glass-like and impervious to liquid
- Ware: Finished pottery products
- Wax Resist: A method of decorating pottery by applying wax to the surface that prevents glaze from adhering
- Wedging: A method of kneading clay to remove air bubbles and prepare it for use
- Whitehard: A stage of clay that is dried to a point where it is nearly as hard as bone dry but can still be carved