All clays used for this process is mid-range stoneware. I use white, black, and a speckled clay body, the exposed clay service and specialty glazes make these pieces unique. They are fired in an electric kiln to a temperature of 2350 F. The glazed pieces are deep blue, golden ambers and rich greens, decorated with an oriental flair. The interesting service of the black and speckled clay, remain unglazed, this is ideal for my garlic jars and bird feeders. All pieces are ovenproof, dishwasher safe, and microwavable. Although it is not advisable to microwave the black clay as it becomes too hot, this is due to its high iron content.