Talking about the changing process of paper.

Ancient ancestors mainly recorded by knotted ropes, and later gradually invented writing, and began to use Oracle Bone Inscriptions as writing materials. Later, bamboo and wood chips (bamboo slips) and silk were found and used as writing materials. But paper was invented because silk was too expensive and bamboo was too heavy. According to research, the production of paper began in the Western Han Dynasty. From 65438 to 0957, Shaanxi Provincial Museum excavated a batch of artifacts named "Baqiao Paper" from a Western Han Dynasty tomb near Baqiao in the eastern suburb of xi, and its production date was no later than the era of Emperor Wu of the Western Han Dynasty. Later, paper fragments of the Han Dynasty were unearthed in Luonaoer, Xinjiang, Juyan, Gansu and other places, about 150 ~ 200 years earlier than the paper made by eunuch Cai Lun from the early Eastern Han Dynasty to Yuanxing. However, we should also see that although paper was invented long ago, it was not widely used at first, and government documents were still written in bamboo slips and silk books. In Xian Di, Zuo Bo, a native of Donglai, improved the previous paper-making method and further improved the paper quality. The paper he made is white, delicate, soft, uniform and bright, and the paper quality is particularly good. Known as "Zuo Bo paper" in the world, especially five-color stationery and high-grade stationery.

From the archaeological findings so far, the invention of papermaking was not later than the early Western Han Dynasty. As early as the Western Han Dynasty, China had invented papermaking with hemp fiber. Su Song's paper spectrum: "Shu people use hemp, Min people use tender bamboo, northerners use mulberry bark, Tunxi people use rattan, Hairen use moss, Zhejiang people use wheat flour and straw, Wu people use cocoon, and Chu people use paper." Papermaking used to be made by hand. First, take the flexible plant fiber, boil it, mash it, make it into mucus, make it into baskets, make it into films, dry it a little, and press it with a heavy object. Most of the paper used today is mechanical paper. Most of the paintings and calligraphy works that have existed for more than 1000 years are made of mulberry paper.

Paper is widely spread and used by people, and papermaking technology is further improved. Before the Jin Dynasty, the paper-making area was concentrated in Luoyang, Henan Province, and gradually spread to Vietnam, Sichuan, Shao, Yang, Anhui, Jiangxi and other places, with increasing output and quality. Paper-making raw materials are also diversified, and there are many names of paper. Such as bamboo curtain paper, the paper has obvious lines, and its paper is tight, thin and even. Tunxi has rattan paper with rattan skin as raw material. The paper is smooth and white as jade, leaving no ink marks. Dongyang has fish egg paper, also known as fish note, which is soft and smooth. Jiangnan uses straw and wheat straw fiber to make paper, which is yellow and rough and difficult to write. In the north, mulberry bark fiber is used to make paper, which has excellent texture, white color, light softness and strong tensile force, and the paper grain tears like cotton silk, so it is called cotton paper. Cai Lun has a wide range of papermaking raw materials. Paper made of rotten fishing nets is called net paper, and paper made of rags is called cloth paper. At that time, the rags of fishing nets were classified as hemp fibers, so they were collectively called hemp paper.

In order to prolong the life of paper, the Jin Dynasty has invented a new technology of dyeing paper, that is, impregnating paper with yellow tiller boiling juice, some of which are written first and then dyed, and some are dyed first and then written. Impregnated paper is called dyed yellow paper, which is natural yellow, so it is also called jute paper. Yellow paper has the function of killing insects and moth.

In the Jin Dynasty (4th century), paper finally replaced silk as the main writing material. Cai Lun has played a great role in promoting the production of hemp paper and leather paper. Although he is not the inventor of papermaking, his historical position as a technical innovator and organizer should be affirmed.

In the 8th century, paper was widely used in China. In the following centuries, China exported paper to all parts of Asia and kept the secret of papermaking strictly. In 75 1 year, there was a conflict between the Tang Dynasty and the Arab Empire, and the Arabs captured several China paper makers. Soon, the paper industry rose in Samarkand and Baghdad. In this way, papermaking gradually spread all over the Arab world, where paper was widely used and then spread to North America and Europe through Arab countries. According to historical records, the first paper mill was established in Europe more than 0/000 years after Cai Lun invented papermaking. Although the modern paper industry has developed, its basic principle is still the same as that of Cai Lun. Nine times out of ten, the raw materials for papermaking have been replaced by wood pulp, but the raw materials for making high-grade printing paper, cigarette paper, rice paper and typing wax paper are still nothing more than rags, bark, hemp heads and waste fishing nets used in Cai Lun.