There are three kinds of calligraphy seals: name seal, leisure seal and appraisal seal. Among them, the collection seal is a seal for appreciation collectors. According to records, the seal of treasure also began in the Tang Dynasty and became popular after the Song Dynasty. It is used to seal precious cultural relics, such as paintings, calligraphy and books. What I read more is "Treasure of Kangxi Imperial Travel" and "Treasure of Qianlong Imperial Travel".
A seal, also known as a seal, is a stationery printed on a document to indicate identity or signature. Generally, seals are dyed with pigments before printing. Those that are not stained with pigment and will appear concave and convex after being printed on a flat surface are called steel seals, and some are wax prints printed on wax or wax or envelopes. Made of metal, wood, stone, jade, etc.