1. official seal

2. Financial section

3. Company seal

4. Special seal for contract

5. Special seal for invoice

According to the material classification of printed matter, there are lithograph, jade seal, claw seal, bronze seal, etc.

According to the seal shape, there are single-sided printing, multi-sided printing, overlapping printing, etc.

According to the use of seals, there are private seals, official seals (including urgent seals) and mud seals;

According to the content form, there are famous seals, official seals, interesting seals, collection seals, seals and seals.

According to the shape, there are square printing, circular printing and conformal printing;

According to the form of seal cutting, there are Yang Wen (Zhu Wen) seal, Wen Yin (Bai Wen) seal and Yin and Yang seal;

According to the chronological classification, there are Qin seal, Han seal, Song seal (nine official seals) and so on.