The Konkōmyō Saishō'ō-kyō (Suvarṇaprabhāsottama-rāja-sūtra), which consists of ten volumes, includes a text about the four guardian Buddhist deities and other deities who are supposed to protect the nation.
On February 14, 741 the Emperor Shōmu announced an order to establish Kokubun-ji and Kokubuni-ji temples in each province. At that time it was also decided that each Kokubun-ji temple should keep within its pagoda the Konkōmyō Saishō'ō-kyō sutra written in gold. According to old documents kept in the Shōsō-in treasure house, the governmental studio for sutra copying in gold letters was established for this project, and seventy-one copies of the sutra, which consisted of seven hundred and ten scrolls, were completed in October 746. They were written with gold dust on purple paper.
The set of volumes which is introduced in this article was reportedly kept in Kokubun-ji temple in Bingo (today's Hiroshima prefecture). The ten scrolls are all extant. The gold letters, which were polished by a polisher using a tusk from a hog, are still shiny and standing out against the purple background. These scrolls have gracefulness and dignity, and they deserve to be called the gems of copied sutras of the Tempyō period. 
Masterpieces of Nara National Museum. Nara National Museum, 1993, pp.74-75, no.55.