The invention of paper was written by hand until the third grade.

The inventor of paper was Cai Hou of the Western Han Dynasty, so paper was also called Cai Hou paper by later generations. Papermaking is one of the four great inventions in China. It was invented in Han Dynasty and Western Han Dynasty and improved in Han Dynasty and Eastern Han Dynasty. Papermaking was introduced in China in the Western Han Dynasty (206 BC), and improved in Cai Lun in the first year of Yuan Xing in the Eastern Han Dynasty (105). ?

Cai Houzhi is a kind of paper made of bark, hemp head, cloth, fishing net and other raw materials through crushing, mashing, frying and baking, which is the origin of modern paper. This kind of paper is easy to find, cheap, and its quality has improved, so it is gradually widely used.

In order to commemorate Cai Lun's achievements, later generations called this kind of paper Cai Hou Paper. Paper is the crystallization of the long-term experience and wisdom of the working people in China. Paper is used for writing, printing, painting or packaging.

Sheet fiber products.

Generally, it is made from the aqueous suspension of pulping plant fibers, which is staggered and combined on the internet, preliminarily dehydrated, compressed and dried. China was the first country in the world to invent paper.

According to archaeological findings, during the Western Han Dynasty from 206 BC to 8 BC, China already had hemp fiber paper, which was rough, small in quantity, high in cost and not popular.

With regard to the origin of papermaking, historian Ye Fan once said in the Biography of Cai Lun in the Later Han Dynasty that paper was invented by eunuch Cai Lun in the first year of Han Yuan Xing (A.D. 105). In fact, it has been recorded in ancient books that before Cai Lun' invented' paper, Cai Lun's portrait was already in use.

As mentioned in the Biography of Jia Kui in the Later Han Dynasty, in the first year of the founding of the People's Republic of China (AD 76), Emperor Zhang Han ordered Jia Kui to select 2,000 students with excellent grades and awarded them "one for Jane, one for Paper and one for Classics". This shows that books were copied on paper at that time, nearly 30 years earlier than Cai Lun's papermaking. In the history of Dongguan, only "Cai Lun's classic works are like paper". The authors of A History of the East, such as Serina Liu and Yan Dou, are Cai Lun's contemporaries. If Cai Lun invented paper, they wouldn't fail to record it.

Since the 20th century, due to the discovery of ancient paper in the Western Han Dynasty, Cai Lun's idea of inventing paper began to waver and was later rejected. Although Cai Lun was not the inventor of paper, he was still the innovator and promoter of paper-making technology.