A large number of canvas samples from paintings by 116 French artists is analyzed for fiber type and weight. Results are categorized chronologically as well as by artist, and it may be seen that prior to the end of the 18th century, hemp canvases were most common, with linen supplanting hemp by the beginning of the 19th century and cotton-linen blends and cotton making their appearance by the end of the 19th century. The method of fiber analysis is described in an appendix.