Why did Bi Sheng's wooden movable type experiment fail, but the Western Xia people succeeded?

Wen | Li Chonghan

There is the Song generation, and they are especially attentive to books. Bi Sheng's invention represented a trend in the book publishing and printing industry at that time, and new technologies were bred in the golden age of engraving and printing. In 1193, the 67-year-old Zhou Bida went to Tanzhou as a magistrate after being deposed, and inspired by the movable type printing method introduced by Shen Kuo, "replaced and copied with clay copper plates", placed the prepared clay movable type on the copper plate (copper's heat transfer is better than iron), successfully typeset the work "Yutang Miscellaneous Records" (Yutang is the old name of Hanlin Yuan), he informed his friend Cheng Yuancheng of the good news, and became the "first person" to print books in the Central Plains according to bi sheng movable type printing method.

After returning to his hometown, Zhou Bida developed his hobby of engraving books into a career, and in Jizhou (present-day Ji'an, Jiangxi), he presided over the engraving of "Wenyuan Yinghua" (1000 volumes) and "Ouyang Wenzhong Gongji" (153 volumes), achieving a model of private engraving, in the face of the million words of "stopping printing three or two books", Zhou Bida still chose engraving and printing, but unfortunately, his "Miscellaneous Records of Yutang" printed in clay movable type did not exist, and now people have no chance to see the actual objects. In 1965, archaeologists discovered fragments of the "Buddhist Sayings and Temples of the Infinite Life Sutra" during the demolition of the White Elephant Pagoda on the outskirts of Wenzhou, Zhejiang Province, are considered to be "the earliest historical witness of Bi Sheng's movable type technology", and there is controversy in the academic circles as to who the "earliest surviving clay movable type print" was spent. Some people think that it is the "Wei Mo Jie Shu Jing" (printed in the early 12th century, excavated in Wuwei, Gansu Province in May 1987), and some people have raised objections, after all, when identifying the movable type version, "the difference between the clay character, the wooden character and the copper character print is between a few micro", it is not clear whether it is a clay movable type or a wooden movable type type printing, Bi Sheng's printing technique is an indisputable fact for the transformation and use of the Western Xia people, and the excavated Xixia movable type book is evidenced by it.

How can I tell if it's printed by movable type instead of engraving? If there are words such as "newly printed movable type", "take the word", "compose the word and dice" in the inscription, there is no need to suspect that it is movable type printing; if there is no clear evidence, it can be observed whether the printed copy has uneven ink color, font size is not equal, stroke thickness is different, digging supplemental printing, stamping and supplementing the words. The Vimalaya Sutra conforms to the above description: the glyphs vary in size, the fonts are fat and thin, the ink print is light and heavy, and some words have obvious broken edges, which is not excluded from the mud movable characters that are "easy to fall off the corners". Judging from the surviving Movable Type prints of The Western Xia, the Western Xia people have experienced the stage from rough clay movable type printing to more delicate wooden movable type printing.

There are more than 6,000 Xixia scripts modeled on Chinese characters, which is much easier to make a set of movable characters than tens of thousands of Chinese characters, and the Western Xia takes Buddhism as the state religion, and when the demand for printing a large number of Buddhist scriptures appears, officials in the Western Xia government agencies who are in charge of movable type printing began to appear, leading the printing activities. At present, the earliest wooden movable type plate print found in the world is the Xixia Buddhist scripture "Auspicious All over the Mouth and the Continuation" (the second half of the 12th century, late Western Xia) excavated in 1991 in the Baisigou Square Pagoda in Helan County, Ningxia, which has many characteristics of movable type versions in ink color and glyphs, and has unique characteristics, and some character lines have different lengths, ink colors, and even lines of a certain curvature, which the scholar Niu Dasheng called interlaced "bamboo pieces" marks. Compared with Bi Sheng's clay movable type typesetting method, wood movable type printing is different in operation, when the lines are arranged, they are separated by bamboo pieces, and then filled with broken wood chips, fixed word molds (omit heating steps), and only when the interlaced "bamboo pieces" are not processed properly will leave an imprint between the lines.

Why did Bi Sheng's wooden movable type experiment fail, but the Western Xia people succeeded? The difference is in what material is used to fix the wooden movable type. The liquid adhesive agent used by Bi Sheng is easy to soak the wooden word mold, and stick to the wooden model, it is not easy to take it off, cleaning is quite troublesome, the Western Xia people switched to bamboo sandwich wood movable type mold, and then used broken wood chips to fill and mash the fixed word mold, the problem was solved. Of course, there is no shortage of experiments in the Central Plains to print movable type with various materials, but most of them have not been recorded, and the related prints have very few surviving, fortunately, with the records of The Yuan Ren Wang Zhen, we can see the whole process of wood movable type printing.