[Arun2009]

One often comes across the term "valkala" in Indian scriptures, which means clothes made of tree bark, usually in the context of asceticism. E.g., see here: https://sanskritdictionary.org/valkala

Apparently, someone wrote a paper about it: "Barkcloth in India-Sanskrit Valkala", https://www.jstor.org/stable/597920