It is understood that most bamboo paintings in Zheng Banqiao have inscriptions, which will indicate the year, inscriptions and other information. However, there are also a few works without signature or only seals without signature.

These unsigned works may not be signed in time because of special circumstances or some reasons at that time. In addition, there are some works that have forged or imitated Zheng Banqiao's style in history. These fake and shoddy products often lack real artistic value and are easy to mislead consumers.