Medievalists.net reports that Adam Gacek has published a paper describing a thirteenth century recipe for Arabic papermaking. The recipe states that the paper was made from the bark of fig trees, rather than hemp or flax.
The article includes a link to the original paper.
An abstract from Gacek's On the Making of Local Paper: A Thirteenth Century Yemeni Recipe:
On the Making of Local Paper: A Thirteenth Century Yemeni Recipe
By Adam Gacek
Remmm: Revue des mondes musulmans et de la Meiterranee, Vol.99-100 (2002)
Abstract: The present article examines and provides a translation of a thirteenth century recipe for papermaking. The recipe in question originated in Yemen and constitutes the second hitherto discovered description of paper manufacture in the Arabic language. Just as the first recipe contained in the work of Ibn Bâdîs (d. 454/1062), this recipe represents a chapter from a manuscript of al-Mukhtara‘ fî funûn min al-Òuna‘ attributed to al-Malik al-MuÂaffar (d. 694/1294). It describes the making of paper from the bark of fig trees, as opposed to hemp or flax (or their products) mentioned in Ibn Bâdîs’s ‘Umdat al-kuttâb and other Arabic medieval sources.