Loaded-Gas-Fire-KilnPorcelain is similar to stoneware but it becomes vitreous (glass-like) when fired. It consists of kaolin (china clay) feldspar and silica, all in small particles. When fired to a very high temperature these materials fuse and combine the refractory nature of clay with the vitreous quality of glass. Porcelain is thought to have been first discovered in northern China during the Tang dynasty (618-907) after which this white clay was found in the Korean peninsula, where the process was developed and refined. After forming the porcelain work and decorating it while it’s still fairly wet, I bisque-fire it in an electric kiln. I then decorate again, glaze the work with my own glazes and fire it in a gas kiln in a reduction (reduced oxygen) atmosphere to about 1300 degrees C. All porcelain work I produce is food- and liquid-safe as well as dishwasher-safe. It can be microwaved and used in a conventional oven, although it should be placed in a cold oven and warmed slowly.