Tin Oxide Super Fine K&W
Tin oxide is a white or off-white powder produced by oxidizing molten high-grade tin metal. It is typically quite pure, some manufacturers have grades up to 99.999% purity. Tin oxide has long been used to opacify glazes in oxidation (make transparent glazes opaque) at all temperatures. Hand decorated tin-glazed earthenware of the 1700/1800s is the most famous use of tin in glazes (delftware-England, faience-France, maiolica-Italy). While many potter's are keeping this tradition alive today most now use zircon based opacifiers instead.
Tin is also a player in the development of ceramic colours, for example, chrome tin pinks and maroons. Tin with iron in oxidation makes a warmer shade of brown than zirconium.Tin oxide is also variates colours. For example, tin can react with titanium and rutile to completely transform the colour and character of a glaze. Although Tin is expensive, very little is required to produce stunning effects in many coloured glazes
The most widely used and effective opacifying material, giving results that are consistently even. Produces a soft-blue-white in both low and high temperature glazes. 4-7% additions will produce semi-opaque glazes and 8-10% will give full opacity..