Stoneware is a strong, dense clay body fired to mid or high temperatures, about cone 5 to 10 (roughly 1200 to 1300 °C), until it is nearly watertight. It is the most common clay for functional pottery and usually fires buff, grey or brown.
What Is Stoneware?
Digitalfire describes stoneware as a high-temperature body fired dense enough to make functional ware that is strong and durable, typically with only a few percent porosity at its rated cone. Clay makers publish absorption figures, and a well-fired stoneware is usually below about 3%.
Stoneware is the workhorse of most studios. It throws well, especially with a little grog, handles hand building and sculpture, and makes tough everyday mugs, bowls and plates. Colours range from white and buff to speckled, red and dark brown, depending on iron and other materials in the body.
There are mid-fire stonewares for cone 5 to 6 and high-fire ones for cone 9 to 10. The two aren’t interchangeable: a cone 10 stoneware fired to cone 6 stays porous and weak, and a cone 6 stoneware fired to cone 10 may bloat or slump.
For most beginners, a grogged mid-fire stoneware is the friendliest clay to learn on, which is why many community studios use one as their house clay.
This pottery glossary entry from Le Studio Art Space is general educational content. Always follow the clay, glaze and kiln makers’ data for your own materials and equipment.