A decomposed granite-type rock. To be classified as clay the decomposed rock must have fine particles so that it will be plastic (see definition below). Clays contain impurities which affect color and firing temperatures.
New cards
3
wedging
Process of kneading clay to make it homogenous; ridding the clay of all air pockets.
New cards
4
greenware
Unfired pottery that is bone-dry. A state in which clay forms are the most fragile.
New cards
5
bisque fire
The first firing of the clay done before glazing. The approximate temperature of this firing is 1880 F.
New cards
6
bisque
unglazed clay, fired once at a low temperature
New cards
7
leather hard
Refers to clay that is dry enough to stand alone but still damp enough to be joined to other pieces or carved without distortion. Clay in this state resembles leather. Hard to bend and soft enough to be carved.
New cards
8
bone dry
Refers to clay which is ready to be fired. All the moisture is gone from the clay. Clay is VERY FRAGILE at this stage.
New cards
9
kiln
Enclosed containers of various sizes- built of refractory brick and heated by electricity, gas, oil, or wood to temperatures from 1500 F. to 2340 F. in which ceramic ware is fired. Also called the “oven” for firing the clay.
New cards
10
fire
term used for baking work in a kiln
New cards
11
handbuliding
One of the oldest craft techniques in which objects are constructed entirely by hand.
New cards
12
form
Three-dimensional shape and structure of an object.
New cards
13
pinch technique
Hand building technique in which a ball of clay is pinched from the center out with the thumbs to create a bowl shape.
New cards
14
coils technique
Hand building technique in which the object is built up with rope like pieces of clay, one on top of another.
New cards
15
slab technique
Handbuilding technique in which flat pieces of clay are joined (clay is flattened and thinned with a rolling pin)
New cards
16
scoring
Roughing up of the surface of clay for joining.
New cards
17
slip
A liquid form of clay used as a glue or as decoration.
New cards
18
glaze
A glassy coating that has been melted onto a ceramic surface. It is used to decorate the piece and to seal the clay surfaces.
New cards
19
underglaze
Colored decoration applied to bisqued clay, then coated with a clear glaze. Typically made of clay slip or raw pigment.
New cards
20
matte
not shiny
New cards
21
glaze firing
The second firing of a piece of pottery which has been coated with glass forming materials. The approximate temperature of this firing is 2300 F.
New cards
22
incising
Carving designs into a surface.
New cards
23
texture
high or low patterns created by pressing or carving down into the clay
New cards
24
sgraffito
decorating technique achieved by scratching or carving through a layer of slip or glaze before firing to expose the contrasting clay body beneath.
New cards
25
cone
A type of thermometer placed in the kiln to indicate when firing is complete. The cone is made of glaze materials and will bend to indicate the end of a firing. (we fire between cones 04-06 which is approx. 1800-2300 degrees).
Studied by 2 people
