These works, though they borrowed the reputation of others, were nevertheless infused with Gu Jingzhou's greatest effort and talent during this period. The Shanghai imitation phase lasted approximately two to three years. During this time, Gu Jingzhou not only studied and copied a large number of actual works by famous Ming and Qing dynasty Yixing masters, broadening his horizons, but also competed with various Yixing masters who had come to Shanghai, causing his skills to mature and stabilize day by day. It can be said that this experience, which is not often mentioned in detail, laid the foundation for Gu Jingzhou's lifelong technical achievements, while also providing him with extremely rich practical experience for his future work in authenticating and identifying genuine Yixing pottery. Today, if we look back at this wave of imitation that occurred in Shanghai during the Republican period with a dialectical perspective, beyond the obvious character "imitation" that everyone can see at first glance, for the Chinese Yixing pottery industry and for artisans like Gu Jingzhou who personally participated in it, there exists a deeper level of meaning. On the surface, this wave took "imitation" as its form. In order to meet collectors' demands to the greatest extent and deceive experts' scrutiny, the antique dealers and Yixing artisans who participated devoted their greatest wisdom and utmost effort. Among these works were both "real imitating real" copies of ancient pieces, as well as "imaginary becoming real" creations. The excellent works among them not only convinced many experienced collectors at the time, who enthusiastically embraced them, but even now, many works are still scattered in various collections as "fakes mixed with genuine articles," with some even regarded as treasures and entering the collections of major museums. Mr. Chen Wenbin of Taiwan once collected a piece called "Gao Yan Ai Seng Da Bin Zeng Mao Hu" (High-rimmed Short Monk Da Bin Zeng Hat Teapot), with an inscription on the bottom reading "Shenglian Ju / Shi Da Bin" (Lotus-Born Residence / Shi Da Bin). In 1993, during Gu Jingzhou's visit to Taiwan, Mr. Chen asked Master Gu to help authenticate the piece. After examining it, Master Gu smiled and replied: "What Shi Da Bin? This was made by me. Doesn't it have my 'Jing Ji' (Jing's mark) characters on it?" But Chen Wenbin searched the entire body of the teapot and could not find any mark other than the inscription on the bottom, so he asked again for clarification. Gu Jingzhou smiled but did not answer. In the spring of 2012, staff from Beijing Poly brought this teapot to Yixing and invited Wang Xiuxian, Wu Qunxiang, Chen Guoliang, and Zhang Qingchen, several master artisans, to examine it together. In Wu Qunxiang's studio, Chen Guoliang used purple sand clay to rub and press around the interior of the teapot body, and only then discovered the imprint of a small "Jing Ji" seal on the inner wall near the handle. After Gu Jingzhou completed this teapot that year, although the bottom bore an imitation mark of Shi Da Bin, he had also stamped his own seal on the clay piece and then attached it to an inconspicuous place inside the teapot body. For what purpose this was done remains unknown, but one thing can be clearly seen: toward these works bearing false attributions, Gu Jingzhou harbored a kind of resistance in his heart, manifested in his concealing the mark in a hidden manner.