Introduction
Material / Clay: Ceramic is one of the oldest forms of arts that are used universally. Its making then started with pottery clay; a material that can be used to build goods that are both serviceable and aesthetical. To understand the basics of pottery clay, one must first familiarize themselves with the three primary types of clay: You have earthenware, stoneware and porcelain types of pottery. These clays all have their character and features, which qualify them for specific uses.
Earthenware
The most basic pottery material used for pottery is the earthenware clay. This is an endogenic, brick-red material, which is made up of many minerals, but mainly kaolinite. Compared to other types of clays, this kind of clay is very permeable and can quickly pull in water which makes it best suited for hand building and form techniques. Still, earthenware clay is not as rigid as the stoneware or porcelain and can easily crack under heat.
The characteristics of earthenware clay are specifically appropriate for many uses in pottery. This type of clay is mostly used to make use value products such as dishes, mugs, bowls, and figurines among others. Because it is fired at a relatively low temperature of 1800-2000◦F or 982-1093◦C, it is cheaper than stoneware or porcelain. Some of the common forms of clay that new potters use are earthenware clay due to its simplicity and cost.
Earthenware clay is normally low fired or dried and then fired at high temperature without a glaze and finally glazed and fired again. The temperature at which they are fired does not enable the potter to bake out the final traces of moisture; so earthenware should not be used for serving warm or cooked food. When using earthenware it is advantageous to glaze them due to their high porosity and therefore sensitivity to water.
Stoneware
Stoneware clay is also frequently used by potters, and probably the most widely recognized. Such clay is usually grayish, olive or brown and contains largely silica and alumina. As compared to earthenwear clay, it is denser and less porous and has greater resistance during firing stage.
Stoneware clay is ideal for forms that will be used and creative forms because it is hard and tough. This clay is fired at considerably higher temperatures than earthenware; the temperatures range of 2200-2400°F (1204-1315°C). Due to the high firing temperature for stoneware, it becomes watertight, and highly durable for holding food products and beverages. Most of the stoneware pots and dishes are microwave oven, oven, dish-washers, and freezer-safe.
As compared to earthenware, stoneware clay is harder to handle because of its density. Proper blending of the clay is only possible when it is done using a pug mill or a powerful mixer. But then due to stoneware clay’s robustness it can be used in commercial potteries where large batches of dishes and other utensils for use in the kitchen are produced.
Porcelain
Porcelain clay is the third major classification of pottery clay. It is almost exclusively made of kaolinite particle and is prized for its homogeneity and brightness. The porcelain is made from clay that is quite different from earthenware and stoneware; it is translucent, denser and less porous. It is also exposed to the highest firing temperatures which ranges from 2300- 2500 F or 1260- 1371 C.
Because of its physical and chemical characteristics porcelain clay is the most suitable for making fine china, dolls and other fragile items. Porcelain pottery for some reason seems to be a more personal type of pottery, and its clarity and historical association with purity makes it a picture perfect type of pottery. However, porcelain clay is not very ideal to work with because it breaks that easily during the drying and firing stages.
Porcelain pottery is also as tough as the stoneware; it is strong and does not break easily. As a result of its high firing temperature and totally non-porous surface it is ideal for holding hot or cold drinks and food. Porcelain dishes are also usable in microwave, dishwasher and freezer .
In conclusion, the understanding of the three kinds of pottery clay; the earthenware, the stoneware, and the porcelain are the most basic important knowledge a beginner pottery needs. Globe specializes in distinct types of clay; each varies in some way specific for its efficiency when used in certain products such as kitchenware, decorations, and sculptures. The possibility to use such a wide variety of clays allows finding the right type of clay for ideas a potter has in mind about their work. This shows that by dedicating time, energy and effort everyone can learn pottery through mastering the basics of the different types of clay.
