What Is Earthenware Clay?

Earthenware pottery is the most affordable type of pottery available.

One of the most common ceramics, earthenware is used to create pottery for decorating. While it can be used for kitchenware, it is more often seen in decorative pottery such as the brownish-orange, clay terra cotta pots or hand-painted Mexican pottery with cultural designs. It is formed by a mixture of materials made into clay and then shaped by a potter, fired in a kiln and glazed to be made waterproof.

Composition

Depending on the region where the pottery is made, such as Japan, India or Europe, there are several different blends of ingredients used in earthenware. These minerals usually include feldspar, quartz, ball clay and kaolin. In its raw state straight from the ground, earthenware may even contain small bits of rock or sand.

Feldspar and quartz are the two most common minerals in the earth's crust and are part of the raw clay that is retrieved from the earth. Kaolin, which is also called china clay, is a soft white clay that is used in the making of china, porcelain, rubber and paint.

Available Colors

Earthenware can be made in various colors along with its typical radiant red base color. The base color is determined by where the clay was retrieved. Different parts of the world have different clays, which can be located in river reds, canyons and even construction sites. The typical color of clay is some type of red. The reddish-orange terra cotta is a color familiar to many, but it can also be black, brown and even cream. Glazes are available in a variety of colors. They should be applied after the clay has dried to make it watertight.

Function

Earthenware is used in terra cotta pots, Dutch blue and white delftware, roofing tiles and items suited to decorative use. It is more affordable than other types of pottery, such as stoneware and porcelain, which makes it more available to the general public.

Although it can be made watertight with glaze, earthenware pottery chips easily, and it is not oven safe. It was traditionally used for water jugs, crocks and painted ceramics, but it is now commonly used in dinnerware such as plates and cups. It can be microwave- and dishwasher-safe, but handwashing is recommended to prevent chipping.

Making Pottery

Earthenware pottery is made by potters who shape the clay on a potter's wheel and mold it to the desired shape. After it is shaped, the clay is fired in a kiln at a temperature of between 1,000 and 1,150 degrees Celsius. It is fired at a lower heat level than other pottery because it cannot withstand higher temperatures; other types of pottery, such as ceramics, are fired at temperatures of 1,200 to 1,400 degrees Celsius. If it is exposed repeatedly to higher temperatures, earthenware will crack or break completely.

History

Pottery has been made from more than 10,000 years, and earthenware pottery has been made virtually the same way since ancient times. Many cultures decorated the pottery to suit their societies, but one that has survived for centuries is Delftware. This type of earthenware was produced in the Netherlands, and it was one of the first European items to be decorated with Asian motifs. Korean artisans decorated their pottery with very ornate patterns and inlays.

References

• Ceramic Arts Daily
• Questions with a Ceramics Conservator