An A to Z of CERAMICS
Ball Clay:
A very plastic clay mined in Devon and Dorset. So named because it was originally mined as lumps or balls weighing about 14kg.
Biscuit Ware:
Also called bisque ware. It is pottery that has been fired but not glazed.
Blunger:
A lareg vat in which rawe materials in both liquid and solid form are mixed together.
Bone China:
The English form of porcelain. It is white, translucent and very strong. The key ingredient is bone ash.
China:
In Britain, this usually refers to bone china but is sometimes used to mean all forms of porcelain. So named because the Chinese were the first to make it.
China Clay:
Derived from feldspar, it is the purest form of natural clay. It has a fine texture and, when fired, burns very white. In England it is mined in Cornwall.
China Stone:
Also called Cornish Stone. It is feldspar less decomposed than china clay and is used as a flux.
Clay:
The essential raw material for ceramics. It is foundin many forms practically everywhere in the world. It is formed when rock breaks down under the action of the weather or by chemical processes- as in the case of china clay.
Earthenware:
Pottery fired at a relatively low temperature. This means that, unlike china, it is not vitrified but is porous, opaque and not so strong. It must be glazed if it holds liquids.
Enamelling:
Enamel colours are metallic oxides fround to a fine powder with a flux added. Fired at a low temperature, it is used to decorate pottery that has already been glazed.
Enamel Firing:
A low temperature firing given to ware decorated on-glaze.
Faience:
A French term for any porous pottery body.
Feldspar:
An ingredient of clays.
Filter Press:
A press used to extract water from slip.
Firing:
Baking ware in a kiln.
Flatware:
Ware such as plates and saucers.
Flint:
Ground flint is mixed with some pottery bodies to control expansion in the kiln.
Gilding:
Using gold or platinum to decorate china.
Glazes:
A thin coating of liuid gass applied to most ware.
Gloss-firing:
The firing given to ware after glazing
Holloware:
Ware such as cups, teapotsand vegetable dishes.
Jiggering:
Shaping flatware such as plates with a machine called a jigger. A pancake of clay is sandwiched between a revovling plaster mould (which forms the front of the plate) and a metalprofile-tool (which forms the back).
Jolleying:
The same principle as jiggering applied to cups- the mould forms the outside and the profile-tool the inside.
Kaolin:
Another name for china clay.
Kilns:
Heated chambers used for baking ware. They vary greatly in size, in the way they operateand the fuel they use. The two main types are ‘intermittent’ and ‘tunnel’ kilns.
Lithographs:
Transfers used to decorate ware.
Moulds:
Normally made of plaster of paris and used extensively for shaping both plastic and liquid clay.
On-glaze:
Decoration of ware after the glaze has been fired.
Porcelain:
The general term for a vitrified, white nd translucent material. In Britain, it normally refers to ware made from a feldspathic body and is thus distinguishe from bone china.
Pug mill:
Rather like as giant mincing machine. It kneads the clay to emove all bbubbles of air and give it an even consistency.
Refractories:
Materials which can wihstand very high temperatures. Fireclay is an example.
Slip:
Clay and water mixed to a creamy consistency. Slip is made as a means of accurately mixing the ingredientsof a pottery body (in which case it is then filter-pressed) or to be used for casting ware in plaster moulds.
Slip casting:
Casting with liquid clay.
Stoneware:
A vitreous but opaque pottery body.
Throwing:
A method of shaping holloware. A ball of clay is thrown onto a revolvong potter’s wheel, is centred and then shaped by the hands.
Under-glaze:
Decoration of ware before glazing.
Vitrification:
When clay is fired one of the constituents-silica-is changed into glass and bonds all the other ingredients together. As vitrification proceeds the proportion of glassy bond increases and its porosity becomes lower. China is fully vitrified.
[tags]porcelain, ceramics, dinnerware[/tags]
The oxide film is, to a large extent, self-repairing. Any break or rupture in the film will quickly reform if the clean, dry surface is exposed to oxygen of the atmosphere for a sufficient period of time. Under normal hotel and restaurant usage, the oxide layer is complete and furnishes protection to the stainless steel flatware.
