The oldest extant woodblock print is a copy of the Mugujeonggwang, the Great Dharani Sutra. The text is the oldest extant printed material in the world for several reasons. The pagoda itself was built in 751, the print had to have been made before that date and no other printed material dates before 750–751 CE. It is 620 centimeters in length and eight centimeters in width. The print contains, on average, eight to nine characters per line. The print has deteriorated due to oxidation and restorations in 1988 and 1989 were carried out to preserve the print.