Inventive Genius: Cai Lun

Cai Lun is the inventor of paper and the paper-making process – one of China’s four greatest inventions.

Cai Lun was born in modern day Leiyang, Hunan (then known by the name of Guiyang) during the reign of Eastern Han Dynasty, sometimes around 50 AD. He served as a court eunuch after 75 AD, after which he started advancing in the court of Emperor He of Han.

At the age of approximately 55 in 105 AD, he managed to invent first stable recipe for papermaking, which was adapted from the traditional low-quality paper that was created by the lower class in the past 200 years. He improved not only the chemical mix of the compound, but also machinery that enabled much faster paper production, pressing and drying. His tactic of suspending sheets of wet fiber in the water, slowly draining the moisture with the presses until the paper was bone dry remained active for more than one and a half thousand years, spreading from China to the Middle East, Europe and then the world. For this invention, Cai Lun was awarded during his lifetime, but has received much higher fame and recognition after his death.

Cai is listed as seventh of the 100 most influential people in history by Michael H. Hart (The 100: A Ranking of the Most Influential Persons in History. Another Chinese who is among the top ten of the 100 is Confucius, who was ranked the fifth. )

Though Cai’s major invention is paper, it is said that he was also very good at making weapons, such as swords.

How Did Cai Come Up With The Paper-Making Idea?

When Cai was an official, he often went into towns and villages to see how things were going. One day in 92 AD, he visited a silk-making shop and saw that there was a thin white layer of slightly fluffy stuff left on the bamboo mat, which could be used for writing.

He was inspired and began to experiment with various materials such as barks, hemp, cloth, nets, etc., and using various ways, such as boil, soak, pound, etc. to make fiber paper. No doubt, he succeeded.

He documented the process and showed it to the emperor He Di along with a finished product in 105 AD.The emperor was greatly pleased, and the paper was called “Cai Hou Paper” in honor of Cai’s contribution. Fine paper officially entered into history.

Modern history of paper-like materials started some six thousand years ago in the delta of Nile, when ancient Egyptians first started using papyrus plant for the manufacture of many things, including papyrus paper. However, papyrus had serious disadvantages and it could be grown and processed only by Egypt and Sudan, so other civilizations strived to find their own paper-like material. While some strived to perfect the use of parchment (dried and stretched animal skin), Chinese focused their attention to real woodbased paper.

Cai Lun died on 121 AD, Luoyang by committing suicide with poison after Emperor An of Han managed to grab the throne left empty after the death of Empress Deng. The emperor then ordered the entire retinue of Empress Deng to be sent to prison, but Cai Lun prevented that fate by ending his life in ritual poisoning after taking a bath and dressing in fine silk robes.

He was remembered very fondly by the Chinese nation after his death. A temple was built and named after him during the Song Dynasty (960-1279). The temple was built in the area where several hundred papermaking families produced paper for China. Today, Cai Lun is remembered as the father of the modern paper industry, and the man who was responsible for the popular use paper all across the world.