The concept of prayer flags partly originates from the culture of worshipping books, using scriptures in various forms. In ancient India, Buddhists treated books as an object of worship. They would write the books, store them in special receptacles and venerate them. Books were written on palm leaves or birch barks in India but when Buddhism reached, the books were written on paper, clothes, wood, metal plates and stone. Short sūtras were carved out on cliff faces, rocks and walls. People believed that they accumulated merit by producing religious books.
This practice of producing and using books for merit-making was also later applied to the medium of flags. It was an innovative way of spreading the teachings of the Buddha or their blessings by harnessing wind power. The tradition of hoisting prayer flags perhaps started with such spiritual background and intention.
Today, in Bhutan there are many kinds of scriptures written on cloth and put up on a pole vertically. In Tibet, where there are less trees, they would print the prayers on cloth or paper in square forms and hang them on ropes horizontally. The prayers came in different sizes and types. Often one would see prayers for increasing one’s lungta or fortune, prayers like oṃ maṇi padme huṃ hoisted for the deceased and prayers like vajra guru hoisted for overcoming obstacles, among other prayers. Prayer flags also come in many colours, normally printed in black ink on white cloth which is the simplest form. Often, there are five colours of cloth representing the five elements, blue for sky, white for clouds or winds, red for fire, green for water and yellow for earth.
Even the little stripes attached to the prayer flags comes in five colours indicating the five elements. Often on the tip of the Bhutanese flag pole, one can find sword indicating wisdom of Mañjuśrī, sun and moon disc under that for the sword to rest, and below that a lotus flower and a wheel or khorlo.