Fu Baoshi, a great painter, often has a note "just in case" in his paintings. It is reported that his painting is not as good as what he saw "just in case". The "idle seal" should originate from the ancient seal of the Warring States, because we can see a large number of "auspicious seals" in the existing ancient seal of the Warring States, such as "Qian Qiu", "Long live", "Qubing" and "Fushou". You can also see a large number of "aphorism seals", such as "respect for things", "external sincerity" and "sincerity". In fact, these so-called "printed words" belong to "idle chapters".