The Porcelain Evaporating Dish 75ml consists of a high quality laboratory grade porcelain, made with uniform wall thickness and dense materials which provides stable mechanical strength and little permeability. When properly used, the glazed pieces can withstand temperatures of 1050 degrees centigrade and the unglazed pieces can withstand temperatures up to 1350 degrees centigrade. The Evaporating Dishes are glazed inside and outside except the bottom surface.