Huachanshi suibi 畫禪室隨筆 "Random notes of Painting the Dhyāna Studio" is a book on calligraphy and painting written during the late Ming period 明 (1368-1644) by Dong Qichang 董其昌 (1555-1536), courtesy name Xuanzai 玄宰, style Xiangguang 香光 or Sibai 思白, from Huating 華亭 in the district of Songjiang 松江 (today part of Shanghai). He obtained his jinshi degree in 1589 and began his career as a junior compiler (bianxiu 編修), and crowned it as Minister of Rites (libu shangshu 禮部尚書) in the Southern Capital Nanjing. His honorific posthumous name is Dong Wenmingong 董文敏公. Apart from painting and calligraphy, Dong Qichang was also a famous poet. He stood in his younger years in the tradition of the Song-period 宋 (960-1279) master Mi Fu 米芾 (1051-1107), but later created a "school" of his own that merged the qualities of the Song with painters from the Yuan period 元 (1279-1368). He wrote several books on painting, apart from the Huachanshi suibi, the texts Huayan 畫眼 (perhaps not Dong's own text), Huazhi 畫旨, and Yunxuan qingmi lu 筠軒清秘錄. His collected writings are called Rongtai wenji 容臺文集.
The first part of the 4-juan-long book discusses the use of the brush and general trends in calligraphy, presents notes on the author's own artworks, and adds critique on ancient works. The second fascicle includes rules for painting, a brief history of different genres, notes on Dong's own works, and critique on famous ancient paintings. The last two fascicles are actually not related to art, due to the fact that the book is written in the style of "brush-notes" essay (biji 筆記) that usually have a very heterogenous character.
The author holds that the excellence of artworks was if the "unexpected" was made the normal (yi qi wei zheng 以奇為正). The refined aspect of calligraphy was the application of brush and ink, and the strength of an overall composition through the linkage of characters. The greatest mistake in calligraphic works was when characters were placed in a uniform mode (weizhi pingyun 位置等勻). When trying to imitate model calligraphies by eyesight (lin tie 臨帖), it was important to understand rightly the spirit of the model, and to "back the sight by [insight into the model's] meaning" (yi yi bei lin 以意背臨). For this reason, only the artworks of the great masters of the past should be used, and not such created by hobbyists (xingjia 行家). Concerning the development of painting between the Tang 唐 (618-907) and the Song period, Dong Qichang asserted that "professionalism" (gong 工) had given way to "playfulness" (chang 暢).
Another reason for the variegated structure of the book might be that it was not written by Dong himself, but a compilation of his disciples who gathered Dong's notes not included in his collected writings Rongtai ji 容臺集. The result of this origin of the book is that some statements contradict each other, and are also different than in other writings of Dong's, like Huazhi, Huayan or Huashuo 畫說, or such found in the supplementary collected writings Rongtai bieji 容臺別集. The text is also found in the series Biji xiaoshuo daguan 筆記小說大觀.