Introduction to prayer flags: Guge is rich in gold and silver. Sutras written with gold and silver juice have been found in Tuolin Temple, Zhabrang, and Piyangdongga, and a huge number of them have been unearthed. This kind of sutra is written on a slightly bluish black paper, one row is written with gold ink, and the other row is written with silver ink. The level of luxury cannot be added.