Preliminary data set of measures from Michiel Coignet’s “reigle platte” and comparison of the weights of substances with data in Kepler’s table of specific gravities in MesseKunst Archimedis. Michiel Coignet, Usus duodecim diuisionum geometricarum, Brussels, KBR, II 769, folio 40r. Data associated with a forthcoming article in Early Science and Medicine, titled “Johannes Kepler and the Exploration of the Weight of Substances in the Long Sixteenth Century.”