CERAMICS

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CERAMICS
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CLAY

• Mud moist, sticky dirt.
• In ceramics, clay is fine-grained,firm earthy
  material that is plastic when wet, brittle when
  dry, and very hard when heated.

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The most common types of ceramic clays are

• earthenware,
• stoneware,
• and porcelain.

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Earthenware

• Earthenware is a low-fire clay that is porous
  and not waterproof.

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Greenware

• Greenware generally refers to unfired pottery.

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Bone Dry

• In ceramics, greenware which is thoroughly room
  dried is said to be bone dry.

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Leather-hard

• In ceramics, leather hard is a state in which
  clay has lost moisture to evaporation, but has
  not yet completely hardened. The clay is damp
  enough to be joined to other pieces with scoring
  and slip.

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Firing

• Firing is the process of baking and hardening
  pottery. Traditional Indian pottery is fired
  outdoors (rather than in a kiln) using various
  fuels including dried animal dung.

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Firing Clay

• Clay is hardened by heating it to a high
  temperature, thus fusing the clay particles.
  Temperature in kilns can reach 2500 degrees.

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Kiln

• A kiln is a furnace in which ceramics are fired.
  Kilns can be electric, natural gas, wood, coal,
  fuel oil or propane.

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Slab Built

• Clay slabs are cut to shape and joined together
  using scoring and wet clay called slip. Slabs can
  be draped over or into forms, rolled around
  cylinders or built-up into geometric forms.

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Slip

• Slip is a fine, liquid form of clay that is
  applied to the surface of a vessel prior to
  firing.
• slip is made by mixing finely ground clay with
  water.

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Slip

• Slip is an inevitable byproduct of working on a
  potter's wheel, its name having resulted from
  potters' use of water to keep the spinning clay
  slippery as it's worked.

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Slip

• It is also used to cement together parts that
  have been formed separately.

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Scoring

• Making scratches or creases in pieces of clay to
  be joined together is called scoring.

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Scoring

• Scoring and applying slip to such roughened
  surfaces creates a bond that holds the pieces
  together.

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Scoring

• If slip acts as an adhesive, and scoring makes
  two pieces of clay like the opposite sides of a
  zipper, their combined action-- a zipped zipper
  with hardened adhesive inside-- should be
  permanent.

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Glaze

• Glaze is a coating of material applied to
  ceramics before firing that forms a glass-like
  surface.

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Glaze

• colored,

• opaque,

• translucent

• or matte.