What's the recommended firing process for clay and glazes?
We generally recommend biscuit firing at 1000-1060C then following with a glaze firing to a higher temperature which matures both the clay and the glaze at the same time. Each clay body and each glaze is catalogued with its firing range: When selecting a glaze for use with a particular clay it is important to select one with a firing range which exceeds the lower figure given for the clay. If this is not done the clay will be underfired, and the glaze consequently may craze. Alternatively, one could biscuit-fire the clay above the lower figure given for the clay then glaze-fire to the firing range of the selected glaze. This method may cause difficulty with glaze pick-up when dipping, although this can be overcome with a flocculant such as Epsom Salts. Bone china is invariably produced in this way. Additionally, the pottery industry use this method for firing earthenware as it increases the durability and craze resistance of the ware.