《梦溪笔谈·书画》
凡是一字有用两个字或三四个字合成的，应该使字字可拆开；如果笔画的多寡相近的，要使它们大小匀称。
凡字有两字、三、四字合为一字者，须字字可拆。若笔画多寡相近者，须令大小均停。
For all characters composed of two or three or four characters, each character should be detachable; if the number of strokes is similar, it should be of uniform size.