According to archaeological findings, as early as the Western Han Dynasty (206 BC to 8 BC), China already had hemp fiber paper. Although the texture is rough, the quantity is small, the cost is high and it is not popular. But paper has appeared. /kloc-in 0/05, Cai Lun summarized the previous experience in Luoyang, the capital of the Eastern Han Dynasty, and improved papermaking, using bark, hemp head, rags and old fishing nets as raw materials. It greatly improves the production efficiency of paper quality, expands the source of raw materials for paper, reduces the cost of paper, opens up new prospects for paper to replace bamboo and silk, and creates favorable conditions for the spread of culture. Regarding the ancient records of Cai Lun's invention of papermaking, The Biography of Cai Lun in the Later Han Dynasty said: "Since ancient times, books and deeds have been compiled with bamboo tubes; People who use it are called paper. Expensive and simple, inconvenient for people. Lun intends to use bark, hemp head, cloth and fishing net as paper. " Later generations revered him as the inventor of China's papermaking.
In the 7th century, China had entered the Sui and Tang Dynasties, and papermaking was quite mature, and the use of paper was also quite common. It is not surprising that you saw someone using paper at that time.