movable type Bi Sheng (990–1051) of the Song dynasty also pioneered the use of wooden movable type around 1040 AD, as described by the Chinese scholar Shen Kuo (1031–1095). However, this technology was abandoned in favour of clay movable types due to the presence of wood grains and the unevenness of the wooden type after being soaked in ink. In 1298, Wang Zhen (), a Yuan dynasty governmental official of Jingde County, Anhui Province, China, re-invented a method of making movable wooden types. He made more than 30,000 wooden movable types and printed 100 copies of Records of Jingde County (), a book of more than 60,000 Chinese characters. Soon afterwards, he summarized his invention in his book A method of making moveable wooden types for printing books. Although the wooden type was more durable under the mechanical rigors of handling, repeated printing wore down the character faces, and the types could only be replaced by carving new pieces. This system was later enhanced by pressing wooden blocks into sand and casting metal types from the depression in copper, bronze, iron or tin. This new method overcame many of the shortcomings of woodblock printing. Rather than manually carving an individual block to print a single page, movable type printing allowed for the quick assembly of a page of text. Furthermore, these new, more compact type fonts could be reused and stored. Wang Zhen used two rotating circular tables as trays for laying out his type. The first table was separated into 24 trays in which each movable type was categorized based on a number corresponding with a rhyming pattern. The second table contained miscellaneous characters. The set of wafer-like metal stamp types could be assembled to form pages, inked, and page impressions taken from rubbings on cloth or paper. In 1322, a Fenghua county officer Ma Chengde () in Zhejiang, made 100,000 wooden movable types and printed the 43-volume Daxue Yanyi (). Wooden movable types were used continually in China. Even as late as 1733, a 2300-volume Wuying Palace Collected Gems Edition () was printed with 253,500 wooden movable types on order of the Qianlong Emperor, and completed in one year. A number of books printed in Tangut script during the Western Xia (1038–1227) period are known, of which the Auspicious Tantra of All-Reaching Union, which was discovered in the ruins of Baisigou Square Pagoda in 1991 is believed to