Movable type printing sets single pieces of type into a page, and when the printing is done the page is broken up and the type can be used again. The type might be of clay, of wood, or of bronze.
In the Qingli years of the Northern Song, the commoner Bi Sheng invented printing with clay movable type, as recorded in Shen Kuo's Dream Pool Essays.
Wang Zhen's Treatise on Agriculture of the Yuan carries as an appendix a method for making movable type and printing with it, which describes wooden type and the revolving type tray in detail.
In the Qianlong years of the Qing, the Wuying Hall printed the Juzhenban collection with wooden type, and movable-type printing reached large-scale use by the court.
Movable Type Printing is the class in the chapter on Sciences on printing books from single pieces of type. From the clay type of Bi Sheng in the Northern Song, to the wooden type of Wang Zhen in the Yuan, to the wooden-type editions of the Wuying Hall in the Qing, movable type let the pieces be taken apart and set again into another book.
