Although the origin of ancient seals is still controversial, the opinions that seals appeared in the Spring and Autumn Period 3,000 years ago are quite consistent. In Zuo Zhuan and Twenty-nine Years of Xianggong, there are words related to seals. These are enough to prove that seals have been used in social activities as early as the mid-Spring and Autumn Period. However, during the hundreds of years from the Western Zhou Dynasty to the Spring and Autumn Period, there was no reliable seal or sufficient information to be found. Most of the earliest seals we can see now are ancient seals in the Warring States period.
The seals in the Warring States period were collectively called "seals". Many features of ancient seals are still unknown to us. Zhu Wen's seals are all cast, and most of them are equipped with wide edges. The lines of the seal are as thin as a millimeter, forming a sharp contrast; The ancient seal in white language is added with side columns, or with vertical grids, cast characters or chisels in the middle. The ancient seal of the Warring States period, the private seal is smaller than the official seal and suitable for wearing; Mainly square, there are various irregular shapes. In addition to the name and official position, it is also engraved with auspicious language and vivid animal patterns, as well as a large area of branded horse prints. There are also gold, jade, pottery and other materials.
These ancient seals have the following characteristics:
First, gradually formed a writing system suitable for the surface of the seal;
Second, there are a lot of yinyin, which is obviously caused by practicality and convenience;
Third, the printing forms are extremely rich, which fully shows the lofty personality and aesthetic orientation of the form at that time;
Fourthly, due to the evolution and differentiation of characters and the separatist regime of princes, the characters and styles of Xi seal show obvious regional color.