I use porcelain for most of my pottery. All pots are microwave and dish-washer safe, except those with gold leaf and crackle glaze. All glazes are food safe and lead free. Porcelain is not made for oven use.
Stoneware clay is used for ovenware, like casseroles and dinner plates. Special care should be taken to prevent rapid temperature changes. Extreme heat or extreme cold can cause damage and cracking. Never take the casserole directly from the refrigerator to a hot oven. Place the room temperature casserole into a cool oven and gradually heat the oven to the temperature desired. Remove from the oven to a draft free, dry surface. Let the casserole cool before putting into the refrigerator. All the glazes are food safe and lead free. All pots are microwave and dish-washer safe.