The world's first movable type printing technology for paper books was made of porcelain materials and was invented around AD 1040 in China during the Northern Song Dynasty by the inventor Bi Sheng (990–1051). The earliest printed paper money with movable metal type to print the identifying code of the money was made in 1161 during the Song Dynasty. In 1193, a book in the Song dynasty documented how to use the copper movable type. The oldest extant book printed with movable metal type, Jikji, was printed in Korea in 1377 during the Goryeo dynasty.