After more than three years of effort, the manuscript of *Purple Tones, Rare Echoes: A Study of Gu Jingzhou's Zisha Art* has finally met with readers. The successful publication of this book has benefited from the tremendous help of many teachers and friends, and here we wish to express our heartfelt gratitude. We thank Mr. Ding Jinsong for his far-sighted vision and overall coordination; we thank Teacher Xu Xiutang for his repeated painstaking efforts in thorough planning and for composing poems for the rubbings; we thank Teacher Pan Chiping and Teacher Deng Junshu for personally proofreading and enriching the materials; we thank Teacher Gao Zhenyu for his erudite citations in writing the preface; we thank Ms. Wu Jufen, Teacher Wang Shixian, Teacher Zhou Guizhen, Teacher Ge Shaopei, Teacher Ge Taozhong, Teacher Zhao Jianghua, Teacher Wang Xiaolong, Teacher Gao Yingzi, Teacher Zhu Jianglong, Teacher Shi Xiaoming, Teacher Wu Dongyuan, Mr. Chen Yinglin, Ms. Li Fumei, Mr. Wang Jijun, Mr. Xu Jianrong, Mr. Dai Gumin, Mr. Wang Jian, and Mr. Chen Yong for providing abundant documentary and photographic materials; we thank Teacher Xu Handang, President Shi Juntang, Teacher Wu Qunxiang, Teacher Li Ming, Teacher Xu Li, and Ms. Sun Ping for their invaluable advice, which helped us avoid difficulties and pursue easier paths; we thank Mr. Lin Weijian, Mr. Wang Lite, and Mr. Kou Xiaoshi for their photography, rubbings, and line drawings, which have greatly enhanced this book; we thank Miss Cao Haiyan for her long-term assistance in conscientiously collecting and organizing materials without regard for compensation. We thank Mr. Lu Zhichang for his brilliant binding design, and finally we wish to especially thank Teacher Zhang He of SDX Joint Publishing Company for tirelessly completing the manuscript review and personally serving as editor. Due to time constraints and our limited talents and clumsy planning, omissions are inevitable. We hope that experts from all quarters will not spare their precious jade but offer criticism and corrections.