Salt Glaze: Westerwald stoneware was fired at about 1,250 degrees Centigrade which is very hot. At that temperature regular table salt vaporizes. The vaporized sodium from the salt forms a flux with the surface of the clay and the result is a glazed surface. If you want to get a feel for the salt glaze process and how it can be adjusted to produce a range of results you should visit this site. It will open in a new window which you can close to return to this page.
Cone 10: The temperature in a kiln has a major impact on the results of a firing. Good quality control and consistency requires the potter to know what temperature is needed and if and when his kiln has reached that temperature. I was surprised to learn that several companies actually sell clay "cones" that will soften with heat and bend over when a certain temperature is reached.
Westerwald: is a part of Germany which is described more completely in Wikipedia. The use of local clay for manufacture of pottery has been established for hundreds of years.
Cobalt Blue Glaze: The generic version of Westerwald stoneware will have a grey background decorated with a bright blue. The blue is the result of a Cobalt Blue Glaze and is applied in a two step process. The clay article is first heated to about 900 Centigrade and salt glazed. It is allowed to cool and a cobalt blue glaze is applied. It is then re-fired at 1,200+ degrees to create the finished stoneware.
