Wiktionary
banana paper
n. 1 paper made from part of the stem of the banana plant 2 paper made from banana fibre
Wikipedia
Banana paper
Banana paper is used in two different senses: one refers to a paper made from the bark of the banana plant and which is mainly used for artistic purposes; the other to paper made from banana fiber obtained, through an industrial process, from stems and the non-utilizable fruits. This paper can be either hand or machine made.
The banana agricultural industry processes of bananas every year (with planted). As a result of pulling apart the banana bunches from the main stem, there are leftover stems which contain 5% of fiber useful for the manufacture of paper.