Once Fired Ceramics
Once-fired ceramics is a technique where you fire from the greenware state straight through to the clay's vitrification temperature. There is no separate bisque firing; it is all done at once. The range of temperature depends on the clay and glazes being used. You can once-fire with any kind of clay, though it tends to be more stressful on the clay body. People do it to save time and energy and to achieve certain affects. It is commonly done in more atmospheric firings: wood, salt and soda, however can be done in regular gas or electric kilns as well.