Seal-cutting is traditionally listed along with painting, calligraphy and poetry as one of the "four arts" expected of the accomplished scholar and a unique part of the Chinese cultural heritage. A seal stamp in red is not only the signature on a work of calligraphy or painting but an indispensable touch to liven it up.

The art dates back about 3,700 years to the Yin Dynasty and has its origin in the cutting of oracle inscriptions on tortoise shells. It flourished in the Qin Dynasty of 22 centuries ago, when people engraved their names on utensils and documents (of bamboo and wood) to show ownership or authorship. Out of this grew the cutting of personal names on small blocks of horn, jade or wood, namely, the seals we know today.

As in other countries, seals may be used by official departments as well as private individuals. From as early as the Warring States Period (475 - 221 B.C.) an official seal would be bestowed as token of authorization by the head of a state to a subject whom he appointed to a high office. The seal, in other words, stood for the office and corresponding power. Private seals are likewise used to stamp personal names on various papers for purposes of authentication or as tokens of good faith.

Seals reflect the development of written Chinese. The earliest ones, those of the Qin and Han dynasties, bear the zhuan or curly script, which explains why the art of seal-cutting is still called zhuanke and also why the zhuan script is also known in English as "seal script". As time went on, the other script styles appeared one after another on Chinese seals, which may now be cut in any style except the cursive at the option of the artist.

Characters on seals may be cut in relief or in intaglio. The materials for seals vary with different types of owners. Average persons normally have wood, stone or horn seals, whereas noted public figures would probably prefer seals made of red-stained Changhua stone, jade, agate, crystal, ivory and other more valuable materials. Monarchs in the old days used gold or the most precious stones to make their imperial or royal seals. Today Chinese government offices at the central level have brass seals as a rule, while offices at lower levels wood ones.

Seals cut as works of art should excel in three aspects - calligraphy, composition and the graver's handwork. The artist must be good at writing various styles of the Chinese script. He should know how to arrange within a limited space a number of characters - some compact with many strokes and others sketchy with very few - to achieve a vigorous or graceful effect. He should also be familiar with the various materials - stone, brass or ivory - so that he may apply the cutting knife with the right exertion, technique and even rhythm. For the initiated, to watch a master engraver at work is like seeing a delightful stage performance.