Royal earthenware is glazed non vitreous pottery which has normally been fired below 1200°C.
Porcelain fired at high enough temperatures to vitrify, are the main other important types of pottery.

Royal primitive earthen ware whatever the color, all terra-cotta, most building bricks,
all European pottery, some of the Chinese; and the fine earthenware which forms the greater part of our tableware today. Earthenware, when fired, is opaque and non-vitreous, soft and capable of being scratched with a knife.

The Combined Nomenclature of the European Communities describes it as being made of selected clays sometimes mixed with feldspar’s and varying amounts of other minerals.Royal earthenware is coming soon with European technology.

Royal earthenware biscuit is fired to temperatures between 1,000 to 1,150 °C and glaze-fired between 950 to 1,050 °C, the usual practice in factories. Some studio potters follow the reverse practice, with a low-temperature bisque firing and a high-temperature glost firing. The firing schedule will be determined by the raw materials used and the desired characteristics of the final product.

Royal Earthenware can be produced at firing temperatures as low as 650 °C and many clays will not fire successfully above about 1,000 °C. Much historical pottery was fired somewhere around 820 °C, giving a wide margin of error where there was no precise way of measuring temperature, and some variable conditions within the kiln.

After firing most earthenware bodies will be colored white, or red. For red earthenware, the firing temperature affects the color of the clay body. Lower temperatures produce a typical terracotta color; higher temperatures will make the clay brown or even black.