Bi Sheng's invention was only recorded in the
Dream Pool Essays by Chinese scholar-official and polymath
Shen Kuo (1031–1095). The book provides a detailed description of the technical details of Bi Sheng's invention of
movable type printing: Bi Sheng also developed
wooden movable type, but it was abandoned in favor of ceramic types due to the presence of wood grains and the unevenness of the wooden type after being soaked in ink. After his death, ceramic movable type may have spread to the Tangut kingdom of
Western Xia, where a Buddhist text known as the
Vimalakirti Nirdesa Sutra was found in modern
Wuwei,
Gansu, dating to the reign of
Emperor Renzong of Western Xia (r. 1125-1193). The text features traits that have been identified as hallmarks of clay movable type such as the hollowness of the character strokes and deformed and broken strokes. The ceramic movable-type also passed onto Bi Sheng's descendants. The next mention of movable type occurred in 1193 when a Southern Song chief counselor, Zhou Bida (), attributed the movable-type method of printing to
Shen Kuo. However Shen Kuo did not invent the movable type but credited it to Bi Sheng in his
Dream Pool Essays. The ceramic movable type was also mentioned by
Kublai Khan's councilor
Yao Shu, who convinced his pupil
Yang Gu to print language primers using this method. The government official
Wang Zhen () improved Bi Sheng's clay types by innovation through the wood, as his process increased the speed of typesetting as well. By 1490, bronze movable type was developed by the wealthy printer
Hua Sui (1439–1513). Wooden movable-type printing became widespread in the
Qing dynasty (1644–1912), but did not replace
woodblock printing, probably because of the expense of creating a font of so many pieces or the low cost of a copyist. == Legacy ==