The chapter at the end is called a masterpiece, which indicates the author's name. Generally close to the square, both yin and yang can be used. If one yin and one yang are above, the yin is below the yang. Generally speaking, there must be a name stamp.
At first, the local seal was an introductory seal or a leisure seal, and its main content was warning words, which were irregular in shape, but small and oval, preferably between the first and second characters. Idle chapters are dispensable.