In the Eastern Han Dynasty and Emperor Wudi's period, after Cai Lun's improvement, a set of relatively stereotyped papermaking technology was formed, which can be roughly summarized into four steps: the first step is the separation of raw materials, that is, the raw materials are soaked in alkali liquor or degummed by cooking, and dispersed into strong fibers; The second is beating, that is, cutting off fibers by cutting and ramming, and sweeping them into pulp; The third is papermaking, that is, the pulp is made into slurry through water seepage, and then the pulp is picked up by a fishing machine (mat) to interweave the pulp into thin and strong wet paper on the fishing machine; The fourth is drying, that is, drying or drying wet paper, and taking it down becomes paper.