the books were printed in China. During the Ming dynasty (1368–1644), Hua Sui in 1490 used bronze type in printing books. In 1574 the massive 1000-volume encyclopedia Imperial Readings of the Taiping Era () was printed with bronze movable type. In 1725 the Qing dynasty government made 250,000 bronze movable-type characters and printed 64 sets of the encyclopedic Gujin Tushu Jicheng (, Complete Collection of Illustrations and Writings from the Earliest to Current Times). Each set consisted of 5,040 volumes, making a total of 322,560 volumes printed using movable type. Korea In 1234 the first books known to have been printed in metallic type set were published in Goryeo dynasty Korea. They form a set of ritual books, Sangjeong Gogeum Yemun, compiled by Choe Yun-ui. While these books have not survived, the oldest book existing in the world printed in metallic movable types is Jikji, printed in Korea in 1377. The Asian Reading Room of the Library of Congress in Washington, D.C. displays examples of this metal type. Commenting on the invention of metallic types by Koreans, French scholar Henri-Jean Martin described this as "[extremely similar] to Gutenberg's". However, Korean movable metal type printing differed from European printing in the materials used for the type, punch, matrix, mould and in method of making an impression. The techniques for bronze casting, used at the time for making coins (as well as bells and statues) were adapted to making metal type. The Joseon dynasty scholar Seong Hyeon (성현, 成俔, 1439–1504) records the following description of the Korean font-casting process: A potential solution to the linguistic and cultural bottleneck that held back movable type in Korea for 200 years appeared in the early 15th century—a generation before Gutenberg would begin working on his own movable-type invention in Europe—when Sejong the Great devised a simplified alphabet of 24 characters (hangul) for use by the common people, which could have made the typecasting and compositing process more feasible. But Korea's cultural elite, "appalled at the idea of losing hanja, the badge of their elitism", stifled the adoption of the new alphabet. A "Confucian prohibition on the commercialization of printing" also obstructed the proliferation of movable type, restricting the distribution of books produced using the new method to the government. The technique was restricted to use by the royal foundry for official state publications only, where the focus was on reprinting Chinese classics lost in 1126