In making porcelain, ceramic material is treated and heated and clay is included in the form of kaolinite. The temperature is between 200C to 1400C. The porcelain material is blazed at high temperature, so it is very tough, translucent, and high in strength. It is white polished cowry and its name is derived from the old Italian word porcella. Porcelain has the properties of low permeability and flexibility, high strength, solidity, glassiness, permanence, whiteness, fineness, significance, fragility, high resistance to chemical attack and thermal shock.



Tables, kitchen ware, sanitary items, fine art, tiles and decorative things are the items made from porcelain. It has a high resistance to the flow of current and therefore porcelain is a good insulating material. Dentists use porcelain in making false teeth, crowns, caps etc.

One material used in making porcelain ware is clay, but actually clay is used only in small proportions to the whole. The main materials used in preparing porcelain are highly variable, but china clay consisting of the mineral Kaolinite is often the most important ingredient. Other materials added with china clay for producing porcelain clay are steatite, glass, steatite, bone ash, quartz, petuntse, alabaster and ball clay.

According to the degree of plasticity the clays are described as long or short. Long clays are of higher plasticity and are sticky. Short clays are of lower plasticity and thus are not cohesive. Porcelain clays have lower plasticity compared to other clays which are being used in making pottery.

The method used for forming, decorating, finishing, glazing and firing ceramic wares is given below-

Forming: The porcelain pottery is formed by pulling clay upward and downward into the desired shape. It can also be formed on a wheel. The throwing of clay seems to be very easy when it is done by an expert potter. Mishandling of the workpiece can destroy the shape of the item.

Glazing: It has been considered that the initial glazes are unintended, and these are due to the existence in the furnace of lime-rich firewood ash, which proceeds to the exterior as a flux. The iron-containing glazes were designed especially for their prominent sound effects on porcelain.

Decoration: The porcelain wares are decorated with the help of cobalt and copper. In modern wares these are chowder-fired at 1000 Celsius, and then they are sent to glazed-firing at a temperature 1300 Celsius. In Chinese and European method both the process are done in single operation.

Firing: it is the process of heating unfired ceramics at high-temperatures in a furnace to prepare their final shapes. Compared to earthen ware or stone ware porcelain is always fired at a higher temperature to vitrify the clay and make it non porous.

There are basically three categories of western porcelain: hard-paste, soft-paste and bone-china. The divisions are made on the basis of the composition of the material (known as paste) used to form the body of porcelain.