Lead-glazed earthenware

In lead glazes, tints provided by impurities render greenish to brownish casts, with aesthetic possibilities that are not easily controlled in the kiln.

[2] At the same time in China, green-glazed pottery dating back to the Han period (25–220 AD) gave rise eventually to the sancai ('three-color') Tang dynasty ceramics, where the white clay body was coated with coloured glazes and fired at a temperature of 800 degrees C. Lead oxide was the principal flux in the glaze.

Polychrome effects (i.e. the colours) were obtained by using the oxides of copper (which turns green), iron (brownish yellow), and less often manganese (brown) and cobalt (blue).

Much of Roman technology was lost in the West, but coarse lead-glazed earthenwares were universal in medieval Europe and in Colonial America.

[8] Lead-glazed earthenwares in Britain include the Toby jugs, such as those made in the late 18th century by Ralph Wood the Younger at Burslem, Staffordshire.