Laffan took a keen interest in Chinese porcelain and engraving, compiling the catalogue (2 vols, 1904–1911) of the Morgan Collection of Chinese porcelains (on display in the Metropolitan Museum until 1915), which was completed after his death by Thomas B. Clarke.Catalogue of the Morgan Collection of Chinese Porcelains. 2 vols. New York: privately printed, 1904-1911. He also provided a preface to Stephen W. Bushell’s catalogue of the W. T. Walters collection of Oriental ceramic art.S.W. Bushell, Oriental Ceramic Art: Collection of W. T. Walters. New York: D. Appleton and Co., 1897. He was a trustee of the Metropolitan Museum, and sat on the acquisitions committee.
