Le Creuset Heritage Stoneware 3.1-Quart Oval Au Gratin Dish, Soleil High-quality exterior enamel to protect against metal marks and other damage Hard-wearing, impermeable finish fired at temperatures as high as 2192F is safe for cutting on with knives Unmatched thermal resistance from -65F to 500F  safe for the freezer, microwave, oven, broiler and dishwasher Less than 1% porosity, blocking moisture absorption which can lead to cracking, crazing and rippling along the interior Unique clay mixture creates a very dense material when fired, maintaining even temperatures and preventing scorching