(Left) Sancai tray. D: 29cm. China, Tang dynasty. Met Museum, NY
(Right) Sancai horse. H: 55cm. China, Tang dynasty. National Museum of Korea
Sancai is probably the best-known Chinese lead-based glaze, containing 55-60% lead oxide (PbO). We know now that lead is poisonous, but there were reasons for its popularity in ceramics. It is a very effective flux which helps the glaze melt and fit the pot snugly. It gives a lovely shine because PbO has a high refractive index, helping to catch and disperse light. Lead glazes can be made directly from crushed raw materials (like old car batteries) without pre-treatment. And they can be fired at low temperatures: around 950˚ to 1000˚ Celsius, so in Chinese terms it is a “low-fired” ceramic. Actually the unglazed body usually needs a higher firing first – known as a “biscuit” firing. The pot below shows the white unglazed “biscuit” body at the base.
Sancai jar and lid. H: 8.3cm. China, Tang dynasty. V&A Museum.
Chemical analysis tells us the elements responsible for sancai colours. The amber-brown comes from iron (2%-5% Fe2O3), green from copper (CuO), and blue from cobalt (with a bit of iron). The straw-coloured glaze is quite similar to the amber but with much less iron (up to 2%). The rare grey-black tones are high in copper (5%+), while brown-black tones are high in iron (8%+).
I’ve found no evidence on the original sources of these colours. Did a potter go for a stroll one day and notice some odd-coloured soil which he used in an experimental glaze? Anyway, here are a few of my favourite sancai pieces.
Sancai camel and musicians. H: 58cm. China, Tang dynasty, 7-8th C. National Museum of China
This fabulous camel carrying a musical troupe was a funerary offering or ming-qi, buried in the tomb of a wealthy Tang official. Note the musicians’ high-crowned hats, large noses and bushy beards, indicating that they are from Central Asia which was the source of all things fashionable at the time.
Sancai horse and female polo player. H: 35.5cm. China, Tang dynasty. National Palace Museum, Taiwan.
Polo was a popular sport for women in the Tang period, so it's likely that this woman’s right hand once held a polo mallet. Several museums (the Musée Guimet in Paris in particular) have figurines of female polo players on galloping horses but they are mostly painted clay, not glazed like this one. Like the camel-riding musicians, this woman’s head is unglazed. This may be because sancai has a naturally runny effect, which looked artistic on bowls and horses, but rather weird on human faces.
“Egg and spinach” bowl. Diameter: 19cm. China, 17th C, Kangxi period. Bonhams Ltd.
The fascination with sancai continued well after the Tang. The dappled pattern on this 17th C bowl, known as “egg and spinach”, was created in the late Ming or Qing period when potters experimented with archaistic styles. I think it looks like something from the psychedelic 1960s. The brownish-purple (“aubergine”) spots are a particular feature, derived from iron and manganese (not a traditional Tang glaze).
