[1] Once cut off from the tree, the leaves are ordered, cleaned, heated, straightened, and tied together in what is known as an olla book or palm-leaf manuscript.
Their presence in Cambodia is attested with certainty in a 12th-century bas-relief in the Angkor Wat temple, depicting an apsara (female spirit) holding an olla book.
The Chinese visitor Zhou Daguan, who toured the Khmer capital in 1292, also relates in his travelogue that monks would recite daily prayers read from books made of "very evenly stacked palm leaves".
[5] The surviving Khmer sastras are now kept in Cambodian pagodas, the National Library of Cambodia and a multitude of institutes across the world, including Bibliothèque Nationale de France.
Constructed from wood, these libraries were sometimes fitted with a multi-tiered roof, sitting in the middle of small ponds, to protect them from termites.
[citation needed] Palm-leaves gets attacked by mold, insects, moisture and weather, especially in a tropical climate, and in order to preserve Khmer sastras, a strategy of minute copying has been the usual recipe for the Buddhist monks.
[13] According to Vann Bunna of the Cults and Religions Ministry of Cambodia, the Khmer government is urging all pagodas and schools to keep them for future generations.
In March 2017, Prime Minister Hun Sen pledged to buy as many sastra sleuk rith manuscripts as a Siem Reap craftswoman can produce.