Discovery of the New World’s Oldest Extant Metal-Type–Printed Book in Korea through Image Acquisition, Comparison, and Analysis

Image acquisition, comparison, and analysis technology was applied to address questions regarding medieval Korean printing technology that have existed for fifty years. Two nearly identical books of The Song of Enlightenment (南明泉和尙頌證道歌), with Korean treasure status, were investigated based on material properties of metal, wood, and ink. It led the discovery of the new world’s oldest extant metal-type-printed book in the thirteenth century in Korea. One version was identififed as metal-type-printed in early September of 1239, as stated in the inscription. It predates Jikji (直指), the oldest extant metal-type-printed book officially recognized by UNESCO, by 138 years and the Gutenberg 42-line Bible by 216 years. This was a stunning discovery of the history of innovations in printing technology in the thirteenth century from the East. The other version was identififed as woodblock-printed in the Joseon dynasty of Korea between the fifteenth and sixteenth centuries. Omni-directional shrinkage of printed pages was observed from the duplicated woodblock printed version. Ink tones and printing patterns of medieval Korean printing techniques were also signififcantly different and provide important clues for printing technique identififcation. The characteristics of the two books were compared with the Jikji and Bible to fifnd similarities and differences between medieval prints from the East and the West.