Kanin were originally designed only for actual use, but their high artistic quality was recognized approximately after the age of the Sung Dynasty and they became the subject of collection and appreciation and also used as a reference material for tenkoku (seal-engraving).
元は純粋な実用印であるが、宋(王朝)代頃からその美術性の高さが評価されるようになり、蒐集・鑑賞の対象、篆刻の参考資料として使用されるようにもなっている。