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Glossary of ceramics

Bisque or bisque fired (Biscuit fired) – A piece that has been fired to the first lower temperature firing usually in preparation for glazing.

Burnish – to rub the surface of clay with a smooth object like a spoon or pebble to seal the surface before firing for the first time.

Ceramic – what clay transforms into after firing in the kiln.

Coiling – building in clay using long coils of rolled out clay.

Earthenware – lower firing range 1040C- 1160C

Figurative – easily recognisable as something.

Firing – heating clay in the kiln to transform it into ceramic.

Glaze – the coating that is placed on the surface of ceramic to seal and decorate it.

Greenware – Pieces made of clay before they are fired in the kiln for the first time.

Hand building – all the techniques to make in clay that don’t use any large pieces of equipment or machinery including pinch pots, slab building and coiling.

Kiln – purpose built equipment like an oven that can reach extremely hot temperatures needed to fire ceramics. Can be electric, gas or wood fired.

Mocha – a decorative slip technique that uses ph differences to create tiny fingers of colour in slips.

Oxides – decorative mediums/pigments made from metal oxides, carbonates etc usually in powder form.

Oxide wash – an application of oxide to the surface of a bisque fired piece that is then washed off to leave the oxide in the deeper marks highlighting texture.

Pinch pots – creating pieces from clay by pinching out from the centre of a round shape.

Porcelain – smooth, white, high firing clay with translucent qualities.

Raku – Japanese firing technique that uses a gas kiln that means pieces are removed from the kiln at the top temperature and then treated in different ways depending on the decoration wanted.

Slab building – building in clay using flat slabs.

Slip – watered-down clay that is used to stick clay together.

Slips (decorating or coloured) – coloured liquid clay used for decorating pieces made of clay.

Smoke fire – putting bisque fired pieces in a container and lighting a fire around them so that the piece absorb some of the carbon from the smoke to produce a decorative finish.

Stoneware – medium firing range 1180C – 1260C

Terra-siglata – very fine slip made from just the finest particles of clay that don’t settle in water used for burnishing to an extremely smooth surface.

Throwing – creating pieces in clay on a wheel.

Underglaze – pigments in a liquid or pencil medium that can be used to apply colour to greenware or bisque pieces that has a transparent glaze placed over the top to seal them.

Different types of glazes – celedon (usually a semi-transparent fluid glaze), shino (opaque tonal glazes), float (fluid glazes with a base colour and float layer in a second colour), tenmoku (dark browns), crackle (deliberately crazed glazes), lava/crater (glazes that create a highly textured surface with craters), lichen and crawl (glazes that separate into small pieces showing the clay between), crystal (glazes that have crystalline structures formed during firing).

Glaze properties – transparent (clear glaze that shows what’s beneath), semi-transparent (clear glaze with some colour in it), opaque (solid colour that covers what’s beneath), glossy (shiny glaze surface), satin or satin matt (slight sheen on the glaze surface), matt (no shine at all on the glaze surface).

From ChatGPT:

 
  1. Bisque: Unglazed ceramic ware that has been fired once.
  2. Glaze: A glass-like coating applied to ceramic ware that makes it shiny and waterproof.
  3. Kiln: A furnace used to fire ceramics.
  4. Clay: A natural material composed of fine particles that is used to make ceramics.
  5. Slip: A liquid mixture of clay and water used to join pieces of clay together.
  6. Wedging: Kneading clay to remove air bubbles and ensure even consistency.
  7. Pottery wheel: A device used to shape clay into vessels.
  8. Coiling: A hand-building technique that involves building up the walls of a vessel using long coils of clay.
  9. Pinching: A hand-building technique that involves shaping clay by pinching it between the fingers.
  10. Mould: A form used to shape clay into a specific shape.
  11. Fettling knife: A tool used to trim excess clay from a vessel.
  12. Score and slip: A technique for joining two pieces of clay together by roughening the surface and applying slip.
  13. Shrinkage: The reduction in size that occurs as clay dries and is fired.
  14. Underglaze: A type of coloured slip that is applied before glazing.
  15. Overglaze: A type of decoration applied over a glaze.
  16. Stilt: A small tripod used to hold ceramic ware off the kiln shelf.
  17. Sgraffito: A decorative technique in which a design is scratched into the surface of a vessel.
  18. Crazing: A network of fine cracks that appear on the surface of a glazed vessel.
  19. Warping: A deformation that occurs when clay is fired unevenly.
  20. Foot: The base of a vessel that comes into contact with a surface.
  21. Incising: A decorative technique in which a design is cut into the surface of a vessel.
  22. Porcelain: A type of ceramic that is white and translucent.
  23. Stoneware: A type of ceramic that is fired at high temperatures and is strong and durable.
  24. Earthenware: A type of ceramic that is fired at low temperatures and is porous.
  25. Terra cotta: A type of earthenware that is reddish-brown in colour.
  26. Raku: A Japanese firing technique that produces unique, iridescent glaze effects.
  27. Cane handle: A handle made from a coil of clay that is shaped like a cane.
  28. Teapot spout: The part of a teapot through which tea is poured.
  29. Teapot lid: The cover of a teapot that fits over the top of the pot.
  30. Teapot handle: The handle of a teapot that is used to lift and pour the tea.
  31. Tongs: A tool used to handle hot ceramic ware.
  32. Grog: Fired clay that has been crushed and added to clay bodies to improve their strength.
  33. Casting: A technique for making ceramics by pouring liquid clay into a mould.
  34. Press moulding: A technique for making ceramics by pressing clay into a mould.
  35. Slab building: A hand-building technique that involves using flat pieces of clay to construct a vessel.
  36. Burnishing: A technique for polishing the surface of a vessel by rubbing it with a smooth object.
  37. Terra sigillata: A thin, highly polished slip used for decoration.
  38. Engobe: A coloured slip used for decoration.
  39. Peephole: A small hole in a kiln through which the firing process can be observed.
  40. Cone: A small, pyrometric object that melts at a specific temperature
 
  1. Decal: A transfer design that is fired onto the surface of a ceramic piece.
  2. Sintering: The process of heating ceramic materials to a high temperature without melting them to create a solid, dense material.
  3. Slip casting: A technique for making ceramics by pouring liquid clay into a plaster mould.
  4. Greenware: Unfired ceramic ware that is ready to be fired.
  5. Refractory: A material that can withstand high temperatures and is used to line kilns and furnaces.
  6. Reduction firing: A firing technique in which oxygen is removed from the kiln, resulting in unique glaze effects.
  7. Oxidation firing: A firing technique in which oxygen is present in the kiln, resulting in bright, clear glaze colours.
  8. Bone china: A type of porcelain that contains bone ash, making it translucent and strong.
  9. Agateware: A decorative technique that creates a marbled effect by mixing coloured clays together.
  10. Crawl: A defect in a glaze that causes it to pull away from the surface of a vessel.
 
  1. Raku kiln: A small, portable kiln used for firing raku ceramics.
  2. Terra sigillata slip: A fine, watery slip used to create a glossy surface on pottery.
  3. Pyrometer: An instrument used to measure the temperature inside a kiln.
  4. Extruder: A tool used to push clay through a die, creating uniform shapes.
  5. Slurry/Slip: A watery mixture of clay used to join two pieces of clay together.
  6. Sprig mould: A mould used to create small, decorative shapes to be added to pottery.
  7. Foot ring: A raised, circular base on the bottom of a piece of pottery.
  8. Crazing: A network of small cracks that appear on the surface of a glazed piece of pottery.
  9. Clay body: A mixture of clay, minerals, and other materials used to make pottery.
  10. Burnout: The process of removing organic materials from a mould before firing it in a kiln.
 
  1. Underglaze: A type of decoration applied to pottery before it is glazed.
  2. Majolica: A type of glazed pottery that is typically brightly coloured and decorated with intricate designs.
  3. Bisque firing: The first firing of a piece of pottery, which removes all moisture from the clay and prepares it for glazing.
  4. Press moulding: A technique for making ceramics by pressing clay into a mould.
  5. Porcelain: A type of clay that is fired at very high temperatures to create a translucent, white ceramic.
  6. Slip trailing: A technique for decorating pottery by squeezing liquid clay out of a small hole in a bottle.
  7. Kiln wash: A mixture of materials that is painted onto kiln shelves to prevent ceramics from sticking to them.
  8. Engobe/Decorating Slip: A coloured slip that is applied to a piece of pottery before it is fired.
  9. Grogs: Crushed pieces of fired clay that are added to clay bodies to improve their strength.
  10. Glaze firing: The second firing of a piece of pottery, which melts the glaze and fuses it to the clay body.