The invention period was in the Western Han Dynasty of the Han Dynasty, and the improvement period was in the Eastern Han Dynasty of the Han Dynasty. After Cai Lun's improvements, a relatively stereotyped papermaking process was formed.

China is the first country in the world to raise silkworms and weave silk. In ancient China, the working people made silk from high-quality silkworm cocoons, and used the remaining bad cocoons and diseased cocoons to make silk floss using the floc method. After bleaching the catkins, there will be some residual catkins left on the bamboo mat.

When the wadding is bleached a lot, the remaining wadding on the bamboo mat will accumulate into a layer of fiber sheets, which can be peeled off after drying and can be used for writing. The by-product of this kind of floating catkins is not large in quantity, and it is called Hehe or Fang Xu in ancient books.

The spread of papermaking. Papermaking was first introduced to North Korea and Vietnam, which are adjacent to our country, and then to Japan. Shortly after Cai Lun improved papermaking, paper became available in Korea and Vietnam. Countries on the Korean Peninsula have successively learned the technology of papermaking. Pulp is mainly extracted from fibers in hemp, rattan, bamboo, and wheat straw.

About the end of the fourth century AD, Baekje learned to make paper with the help of the Chinese, and soon Goryeo and Silla also mastered papermaking technology. Since then, Goryeo's papermaking technology has continued to improve. By the Tang and Song Dynasties, Goryeo's vellum paper was exported to China.

Baidu Encyclopedia-Papermaking (one of the four great inventions in ancient China)