Although our word paper comes from the word papyrus, a reed from Egypt, split, then pressed together to use as a writing surface, paper was made by a process the Chinese used from at least the period of the Western Han Dynasty.
"Raw Materials for Old Papermaking in China," by Tsuen-Hsuin Tsien. Journal of the American Oriental Society, Vol. 93, No. 4 (Oct. - Dec., 1973), pp. 510-519, says that the ancient Chinese used hemp as a writing surface from the Western Han Dynasty (206 B.C.-A.D. 8), mulberry from (A.D. 25-220), bamboo from the middle of the Tang Dynasty, and straw from before the Sung Dynasty. Rattan was the preferred surface from the 3rd to 12th century A.D.
It is thought paper manufacture began when rags in water were pounded and then their wadded fibers stretched out on a mat. There they dried, producing a thin surface. The Chinese used a variety of vegetable fibers, including hemp, jute, flax, ramie, rattan and bark from the mulberry tree, grasses and cotton fibers.
The first treatise on paper was written by Su I-chien (957-995), who mentions that seaweed was used as a writing surface by people in the south seas.