A prayer flag is a colorful panel of rectangular cloth, often found strung along mountain ridges and peaks high in the Himalayas. They are used to bless the surrounding countryside and for other purposes. Prayer flags are believed to have originated with Bon, which predated Buddhism in Tibet. In Bon, shamanistic Bonpo used primary-colored plain flags in healing ceremonies. They are unknown in other branches of Buddhism. Traditionally they are woodblock-printed with texts and images.