The capital city is displaying works of calligraphy on the walls of subway stations for the entertainment of visitors to the Olympics.

Here are some facts about Chinese calligraphy.

ORIGINS OF CHARACTERS: The earliest identifiable characters appeared on bones, tortoise shells and bronze ware during the Shang Dynasty (1600-1046 BC). They are called Jia Gu Wen.

Calligraphy evolved along with characters but did not emerge as a popular art form until the Wei and Jin and the Northern and Southern Dynasties (220-589 AD).

MAJOR CATEGORIES: Seal script, or zhuan shu; official script, or li shu; regular script, or kai shu; running script, or xing shu, and cursive script, or cao shu.

FAMOUS CALLIGRAPHERS: Wang Xizi, Ouyang Xun, Yan Zhengqing and Liu Gongqun, who were well known for pioneering their own styles.

FOUR TREASURES OF THE STUDY: Brush, paper, ink stick and ink stone. To write characters in ancient times, these four things were essential.

-- BRUSHES: Can be hard, soft or mixed. Their handles are usually made of bamboo, wood, lacquer or porcelain; ivory or jade handles are rare and precious.

Hu Writing Brushes from Huzhou City, east Zhejiang Province, are regarded as the best quality. The shafts are usually made of red sandalwood, mottled bamboo, white porcelain or even ivory.

The brush features goat hair, brownish rabbit hair, stiff weasel hair or a mixture of goat and weasel hair.

-- INK STICKS: A unique pigment is used for Chinese traditional calligraphy. Clean water is needed to grind the ink stick. Press the stick hard and rub lightly, slowly and evenly against the ink slab until a thick, liquid ink forms.

HUI MO: Also known as Anhui ink stick, it is the most famous. Made of pines that grow on Huangshan Mountain in central Anhui Province, it is hard and exudes a pleasant scent.

-- PAPER: Quality papers include Xuan paper, produced in Xuanzhou, in Anhui Province, which is considered the best. The paper is soft and fine textured with a good tensile strength and mothproof quality.

-- INK STONES: Features common to all quality ink slabs are the stone's hardness and fineness. Only on a hard, smooth stone, can liquid ink be produced easily.

Duan ink slabs in Zhaoqing City of south Guangdong Province are the best-known. The slabs are made from natural stone found in remote mountains. A good quality ink stick with Duan ink stone will work together to produce extremely durable ink. Enditem.