Mu Gu Jung Kwang Dae Da Ra Ni Kyung
(circa 751 C.E., National Treasure 126)
The world's oldest surviving wood block print, this Buddhist sutra is 6.7 cm wide, 6.228 m long and weighs 65.2 g/m2. Average thickness is 0.080 mm and its density is 0.815 g/cm3. Da Ra Ni is understood to hold mystical power of Buddha. As a medium for furthering one's pursuit of enlightenment, the recitation of Da Ra Ni is believed to bring remission of a sin, spritual merit and ensure a long life.

When it was found in 1966 inside a pagoda of Bul Kuk Sa, a Buddhist temple in Gyung Sang province of Korea, scholars were stunned by the longevity of Hanji. The scroll, printed on Dak (Korean paper mulberry), was intact except for small areas of moth damage on the backside. However, the silk wrapped around the scroll was so decayed that it had to be observed under a microscope before being identified as silk.

Research into this print revealed the level of sophistication in papermaking techniques of that time. In particular, the use of natural formation aid to flow the fiber mixture across the screen and Dochim treatment are proven to be highly innovative.