ExpertAdvice

Q What are the most collectible seals and why are they so popular?

WHAT THE EXPERT SAYS:

Nicolas K.S. Chow, Sotheby's director of Chinese ceramics and works of art, China and Southeast Asia, says: 'Seals rank among the most intimate objects used by scholars. For the legitimacy they lend to an official edict, a painting or a calligraphy, they hold more symbolic power than any other object. You'll rarely find any official document or painting that doesn't have a seal.'

Seals are often the most treasured of all family heirlooms. 'Of all pieces in the palace, the last emperor, Puyi [1908- 1911], took only a set of three tianhuang seals that belonged to Emperor Qianlong [1735-1796] when he fled from Beijing,' Chow says. 'The symbolic importance given to seals at the court dates back at least to the first emperor of the Qin dynasty [200BC], when the saying 'to ride a sedan chair with six imperial seals' first appeared.'

SIGNED AND SEALED:

Chow says a wide range of materials were used. These include stones such as jade (white or green from the plains of Khotan), soapstone from Shoushan in Fujian province (from the finest translucent toffee-coloured tianhuang to more common variegated stones), marble and sometimes rock crystal, organic materials (such as ivory, sandalwood or occasionally bamboo), metals (such as bronze, silver or gold), porcelain and, very rarely, glass.

Animal forms were favoured for their symbolism. 'At the Qing court [1644-1911], large official seals usually carved with dragons were mostly carved out of white or green jade, because of the durability of the material, or sometimes out of sandalwood, the fragrance preventing the seals from being attacked by insects. In the Yongzheng and early Qianlong period, tianhuang - the most precious material - was favoured for smaller, scholarly seals for the emperors. These are usually found on their personal calligraphies or paintings, but they're particularly rare.'