Yizhou shuangji 藝舟雙楫 "Double oars of the boat of arts" is a book on calligraphy written during the high Qing period 清 (1644-1911) by Bao Shichen 包世臣 (1775-1855), courtesy name Shenbo 慎伯, style Juanweng 倦翁, Anwu 安吳 or Xiaojuan Youge Waishi 小倦游閣外史, from Jinxian 涇縣, Anhui. He is therefore also known as Bao Anwu 包安吳.
Bao's book on calligraphy is one of his great four books, Anwu si zhong 安吳四種, the others being Zhongqu yishao 中衢一勺 (hydrology, canal transport, and salt administration), Qimin sishu 齊民四術 (agriculture, ceremonies, penal law, military), and Guanqing sanyi 管情三義 (poetry, rhapsodies).
The book of 6 juan length and an appendix (Fulu 附錄) of 3 juan is divided into two "paddles" or "oars" (ji 楫), the first being a discussion of writings on art (Wenlun 文論, 4 fascicles), and the second one a treatise on calligraphy (Shulun 書論, 2 fascicles). The latter part is separately known as Anwu lunshu 安吳論書.
In the first half, the author discusses various themes of calligraphy, rates contemporary artworks, answers question of his colleague Wu Xizai 吳熙載 (1799-1870) and of his three sons. In the second half, Bao pointed at critical errors in the book Shupu 書譜 and created an abbreviated version of it. He also critically commented the famous model calligraphy Shiqi tie 十七帖, and comments on the calligraphy of Wu Xizai and presents remarks on Wanbai Shanren 完白山人 (i.e. Deng Rushi 鄧石如, 1743-1805).
Bao explained that the first thing to learn was to write with the brush, and that virtually the whole body must be used with all its energy. He also explains that the technique of using the brush focused on individual strokes, which should not only be solid or thicker at both ends, but also full and strong in the middle part.
Unlike most older writers on calligraphy, Bao Shichen was not a friend of Tang-period 唐 (618-907) calligraphy, nor did he believe in the "scholarly discipline" of model calligraphies (tiexue 帖學) created by the Song dynasty 宋 (960-1279). Instead, Bao practically rediscovered the unique calligraphy of stele inscriptions from the Northern Wei period 北魏 (386-534). He held that inscriptions on steles from the Northern Wei had "a definite method of writing, and the characters thus came out freely, with many variations" (Bei biezi you ding fa, er chu zhi zizai, gu duo bian tai 北碑字有定法,而出之自在,故多變態). Tang-period calligraphy, however, had no definite style, and characters were therefore restrained and like produced "from printing plates", i.e., formalistic (Tangren shu wu ding fa, er chu zhi jinchi, gu xing keban 唐人書無定勢,而出之矜持,故形刻板).
The book is included in the series Cuilangganguan congshu 翠琅玕館叢書, Yishu congshu 藝術叢書, Yuyuan congshu 芋園叢書, Yujimiaoguan congshu 玉雞苗館叢書, Guoxue jiben congshu 國學基本叢書, Yishu mingzhu congkan 藝術名著叢刊 and Lidai shufa lunwen xuan 歷代書法論文選.
Format and title of the Yizhou shuangji were later adapted by Kang Youwei 康有爲 (1858-1927) in his Guang yizhou shuangji 廣藝舟雙楫.