Bi Sheng

Bi Sheng was a Northern Song commoner known only from Shen Kuo's Brush Talks from Dream Brook (Mengxi bitan). Shen records that in the Qingli years of the 1040s Bi Sheng carved characters in sticky clay, each as thin as the rim of a coin and each a separate piece, and hardened them in fire. To print, he coated an iron plate with pine resin, wax and paper ash, filled an iron frame on it with type, then warmed the plate so the coating softened and pressed the faces level with a board. He kept two plates, setting one while printing from the other, which made long runs very fast. He tried wooden type but gave it up because the grain was uneven, swelled when wet and stuck to the coating. Shen says that after Bi Sheng died his clay type passed to Shen's own nephews and was kept. A gravestone bearing the name Bi Sheng found at Yingshan in Hubei in 1990 is claimed by some scholars as his.