It is also popular because it is easier to carve than the stones already introduced in this series and is cheaper than those stones. The usual shape of a seal is oblong, but some seals are unusual in form.
青田石的價值雖不及田黃、雞血、白芙蓉，但因它溫潤易刻，反成為最普遍的石材，造型的變化也較大。前期曾提及印石的最初形制為印上有鈕，便於鈐蓋；鈕上有孔，可穿繩佩帶。