What's the difference between iron line seal and imperial seal? Who initiated it?

The difference between iron line printing and Yuzhu printing is that the former is as strong as iron and the strokes are as thin as lines, while the latter is even and round, symmetrical from left to right, just like two chopsticks, hence the name. In calligraphy, the former is Li's [City God Temple Monument] and the latter is Li Si's [Taishan Stone Carving]. Seal cutting is the opposite of seal cutting. Iron line seal cutting is mainly based on "Zhu Wen (Yang Wen)", and both sides are engraved. The seal cutting of the jade seal is mainly based on "Yin Wen", which is slightly rough and slow, and the knife is mainly in one go. Seal script is divided according to the style of the period, divided into big seal script and small seal script, and the font is gradually formed. As for who initiated it, there is no specific distinction. This can be found in the inscription.