The text addresses the question of the urban workshops of diatretic glass operating from the central decades throughout the fourth century AD, confirming the leading role of Rome also as a center of ateliers specialized in sumptuary arts. Starting from the engraved glass, we try to outline a model of the late antique workshop valid not only for this class, but which can
applications in other luxury products. The extensive research process defines the scope of production, the client, the use and the chronology of large groups of glass. The activity of diatretarii, itinerant specialized artisans (like those who worked precious metals) is analyzed and personalities of a high level are revisited and captured.