SnO has been used as pigment in the manufacture of glasses, enamels and ceramic glazes. ZnO affects the melting point and optical properties of the glazes, enamels, and ceramic formulations. It is also used as an ingredient in many dressings, glazes, sauces, soups, and marinades. It is a component in some ceramic glazes and metal patinas. Metals used in ceramic glazes are typically in the form of metal oxides. Glazes containing lithium oxides are used for ovenware. It was also ground into powder to add to glazes for use in ceramics. Copper glazes&colon; are treated completely different than crackle glazes. Clay mould 'biscuit' painted with thick coloured lead glazes, simultaneously, then fired. Some candies or confections may be coated in edible wax glazes. Such glazes are crystalline, in contrast to the amorphous glazes seen in pottery. Calcium oxalate is used in the manufacture of ceramic glazes. Borax is a component of many detergents, cosmetics, and enamel glazes. Gum arabic has a long history as additives to ceramic glazes. Lead was also used for ceramic lead glazes.