The dressing of grinding surfaces of millstones to maintain their “sharpness” is a technique known since ancient times. This was for the most part carried out by randomly pecking the grinding surface. More complex dressing patterns, requiring technical knowledge of the progress of the grain through the stones, is observed on Olynthian hopper-rubbers in the Mediterranean since the Classical Period. Intricate dressing patterns were also applied in Antiquity to rotary querns in Germania, in northern and eastern Gaul, and in certain areas of the southeastern Narbonnese Gaul. Although millstone dressing appears to wane after Antiquity, it was widely adapted in Modern Times and was, in fact, a fundamental aspect of milling as late as the 20th century. Millstone dressing with intricate patterns in Antiquity in the Paris Basin seems to have been common. The study of a collection of millstones from Antiquity allows us to offer a typology of dressing techniques regardless of their means of traction. The recurrence of certain patterns of furrows and their symmetry on both the upper and lower grinding surfaces allows us, based on comparison with patterns on modern millstones, to suggest the direction of rotation. The reasons behind dressing millstones in Antiquity remain still largely unknown.