In its purest form clay is an aluminum silicate mineral kaolinite, with its plastic properties arising from the composition of microscopic platelets that give clay the ability to maintain its shape when molded. In early civilization, potters would retrieve clay from riverbeds where it was deposited. They'd dig up the clay, picking out rocks and sticks and make pots out of raw clay. Today manufacturers used raw materials to make clay bodies, which are mixed as dry ingredients to which water is added and the clay left to de-air in a pug mull where it's extruded into bags and boxed. There are thousands of different types of clay the main types being porcelain, stoneware, and earthenware. All of which can be fired at different temperatures as they mature at different temperatures.
Throwing Clay:
This is the most common process associated with pottery, it involves centering clag on an electric wheel, opening it into a vessel and lifting to shapes walls, creating a symmetrical vessel. However some potters may choose to slab build, in which pieces are rolled out and constructed by hand.
Glazing:
Ceramic glaze is mainly made up of glass which is ground into a powder and mixed with water and binder to allow the glaze to stick vertically. The heat of the kiln causes a chemical reaction in the glaze, altering its appearance with some glazing turning different colours depending on firing temperatures. Some glazes will have one appearance when fired at one temperature and a completely different appearance when fires at another temperature. Glazes can be applied in multiple ways to achieve different effects. Brushing is the most common way to apply glaze, with different brush styles and techniques being used to create patterns and textures. Spraying is another form which creates interesting effects depending on the number of layers used. Dipping can also be used to cover an entire piece or section of a piece evenly. Pouring is usually used to glaze the inside of different vessels.
Firing:
Firing clay concerts the ceramic work into a durable crystalline form, making it easier to handle during the glazing process. Clay is traditionally fired twice, its bisque fired and glazed fired. Bisque firing converts greenware to a durable semi-porous stage which aids the glazing process and burns out organic materials within the clay. Pyrometric cones are used to gauge heat during the firing process. A three-cone system is usually used consisting of a guide cone which is one cone below target temp, a firing cone and guard cone. Bar cones and small cones are used within an adjusted Kiln-sitter which is an automatic shut of device. Cones are the measurement which tells potters the temperature at which to fire clay, as different types of clay have different firing points.
An assortment of furniture is needed to hold and support pieces during firing, shelves, posts, stilts and tile setters are all key pieces. Furniture is designed to withstand repeated heating and cooling at high temperatures without deforming.
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