Potpourri jar ca. 1690-95 Louis Poterat Manufactory The first successful efforts at producing a soft-paste porcelain body in France took place in the city of Rouen in northwestern France during the closing decades of the seventeenth century.1 At this time, Rouen was a major center for the production of faience, the term applied to earthenware decorated with a tin glaze. As no porcelain was yet in production in France until at least 1670, tin-glazed earthen-wares provided a viable alternative to Chinese and Japanese porcelains, since the white surface created by the addition of tin to the glaze allowed potters to decorate both monochromatically in cobalt blue or in a limited palette of enamel colors. However, faience lacked the durability, translucency, and thinness of porcelain, and it is likely that numerous faience makers experimented in order to develop a porcelain body, which was universally held to be superior.Surviving documents suggest that the Poterat family of faience makers