Earthenware Glazes

Earthenware has been the primary clay body of use for potters around the world over the centuries up until modern times. Earthenware clays come in a variety of colours and textures, ranging from white, terracotta and deep chocolate browns, from creamy soft porcelains to rough and grainy raku.

Sajo Ceramics has a wide variety of Earthenware clay and glazes to choose from. We stock Cesco, Mayco and Duncan Crystal glazes, Walker Ceramics, Feeneys and Keane clay bodies to name a few.

Firing Temperatures

Earthenware is fired at temperatures below 1190 degrees Celsius and within the ranges of 950 and 1150 degrees Celsius. The lower firing temperature was formed in ancient times as historically, such high firing temperatures were unattainable in most parts of the world until modern times.

Earthenware can be produced at a temperature as low as 600 degrees Celsius and many won’t be successful at temperatures above 1000 degrees Celsius. Most historical pottery was fired at temperatures of around 800 degrees Celsius giving a wide margin for error as there was no way of gauging the precise temperature and variable conditions within the kiln. Because of the lower firing temperatures required for an earthenware firing, earthenware glazes come in a wider colour range as the lower temperature keeps the colour-giving ingredients within the glaze stable.

Glaze Colour Range

The varied colour range possible in ceramics is usually because of low firing techniques. Due to its porosity, earthenware must be glazed to be watertight and the glazes can form a variety of surface textures, such as matte or glossy and bright or muted colours. They may also enhance the underlying design or texture either unmodified or inscribed, carved or painted.

Generally a contemporary earthenware clay body comprises of 25% kaolin, 25% ball clay, 35% quartz, and 15% feldspar. After firing, most earthenware clay bodies will be coloured white, buff or red. For red clays, the firing temperature affects the colour of the clay body. Usually, earthenware bodies have more plasticity than whiteware bodies making it easier to shape and manipulate on the pottery wheel.