After the iron cookware is cast in the traditional method, a glass particulate called "frit" is applied. This is baked on between 1200 and 1400ºF, causing the frit to transform into a smooth porcelain surface that is bonded to the iron. There is no exposed cast iron on your enameled cookware. The black surfaces, pot rims and lid rims are matte porcelain. The porcelain (glass) finish is hard, but can be chipped if banged or dropped. Enamel is resistant to acidic and alkaline foods and can be used to marinate, cook and refrigerate. Cooking with Enameled Cast Iron Wash and dry cookware before first use. If cookware includes rubber Pot Protectors, set them aside and keep for storage. Enameled Cast Iron can be used on gas, electric, ceramic and induction cooktops, and are oven safe to 500 °F. Do not use in microwave ovens, on outdoor grills or over campfires. Always lift cookware to move. Use vegetable oil or cooking spray for better cooking and easier cleaning. Do not heat an empty Dutch oven or covered casserole. Add water or oil when heating. For added longevity, pre-heat and cool your cookware gradually. Low to medium heat when cooking stovetop provides best results due to natural heat retention of cast iron. Do not use high heat. To sear, allow cookware to gradually come to heat. Brush cooking surface and food surface with vegetable oil just before introducing food into the pan. Use wooden, silicon or nylon utensils. Metal can scratch the porcelain. The heat retention of cast iron requires less energy to maintain a required temperature. Turn the burner down to accommodate. When on a stovetop, use a burner nearest in size to the diameter of the pan bottom to avoid hotspots and over-heating of sidewalls and handles. Use oven mitts to protect hands from hot cookware and knobs. Protect countertops/tables by placing hot cookware on trivets or heavy cloths.