Why do ancient calligraphy works have to be stamped with many chapters?

Chinese painting pays attention to the combination of poetry, calligraphy and painting, so it is more beautiful to add seal script painting. Of course, there are also those that are not stamped. It can be roughly divided into Xiao seal, Hua seal, name seal, collection seal, Zhai official seal and so on. According to their shapes, they can be divided into squares, circles and so on. A small seal refers to an image engraved on it, and the general pattern is relatively simple. The flower seal is engraved with a pattern, which represents one's identity, just as the collection seal refers to the collection of a certain collection or museum, the official seal of Zhai, and a person's residence in ancient times all have a name, such as Yuan and Xiaoxiang Pavilion, usually with a seal on the painting. Someone added an official seal of Zhai, and the painting was passed on to future generations, so they stamped their own collection seal, indicating that they had collected it or seen it, such as Sanxi Hall's classics seal and Qianlong's appreciation. After a long time, the seal is much more stamped.