In the early days of paper-making, the main materials for paper-making were tree bark and rags. At the latest in the early Western Han Dynasty in the 2nd century BC, the paper was introduced in China.
The original paper was produced by hemp fiber or hemp fabric. As paper-making is still in its infancy and the process is simple, the paper produced is rough and has many loose fiber bundles. The surface is unsmooth. It is unsuitable for writing and is generally only used for packaging.
Cai Lun has improved the process of paper-making and has contributed to the improvement of the paper-making process without fully inventing it. He allegedly created a sheet of paper using mulberry, worn fishnet, bark, cloth and other plant fibers. These raw materials could be easily found at a much lower cost so large quantities of paper could be produced.
People started to use rattan for paper-making. Paper can form in a different color and several usages by using rattan (e.g. Yellow rattan paper are used for punishment edict).
Later, the emperor has moved their capital from Loyang (洛陽) to Pianan (偏安), the demand of paper has increased. Wooden slip gradually replaced by the paper book. In order to last the paper for longer, people coated the paper with glue for the pest control.
People started using bamboo for paper-making in the Tang dynasty. It marked a significant breakthrough in paper-making technology. The fiber of bamboo is hard, brittle and easy to break, which is difficult to deal with technically. The success of paper-making with bamboo indicates that the ancient paper-making technology in China has reached a fairly mature level. The quality of the paper produced is getting higher and higher, and there are more and more varieties. Due to the stable political situation and economic development, paper-making in Tang is well developed, which they often use the best quality of paper for copying and examination.
Printing technology became popular in the Song dynasty, the demand for the paper had increased. It encourage the development of paper-making.
The Song dynasty was the world's first official government in history to issue the banknote such as Jiaozi (交子) and Huizi(會子).
Moreover, paper armour was one of the weapon of army in Song dynasty. Paper armour was made by silk paper and functioned as a defend, worn under other armour or by itself.
Furthermore, the Song government officials who had done excellent service to the government were rewarded by the court with presents of paper-printed money wrapped in paper envelopes.