Secondly, the official seal was unified. In the ancient seal of pre-Qin dynasty, the official seal was There are also different forms. The official seal system in Qin Dynasty stipulates that the seal forms are all square, and the seal production is all in white. As for the official seal with low level and humble position, it is half of the square official seal, which is a rectangle, that is, the so-called "semi-pass seal". This is the origin of later generations to distinguish the rank and rank of officials by the size of printed materials. In addition, the square official seal must be marked with the word "Tian" The semi-seal "Ri" character is a boundary. Therefore, one of the important bases for identifying Qin seal is the institutionalization of the use of the boundary. Judging from these Qin seals, the seals near the boundary really occupy the majority.
Thirdly, the specialization of the official seal of Qin Dynasty is another important proof of the establishment of the seal system in Qin Dynasty. Qin uses the small seal in the same language, so it is to use the small seal on the seal.