2) Seal cutting shop: Most of the seals used by painters or brush calligraphy are 30mm*30mm and 45mm*45mm, mostly square seals, and relatively few circular seals. Most of them are (10-15 mm) * (20-40 mm), and hard-pen calligraphy uses square seals.
3) Note: The above data refers to the printing surface size, not the overall size.