International audience From the 1st to the 3rd c. AD, the territory of Istria (present-day Croatia) was a prominent area of olive oil production, famous throughout the Roman world. Olive oil was exported in the so-called Dressel 6B amphorae to northern Italy and the Danubian provinces. The production of these containers was carried out in several workshops established along the Adriatic coast in Istria and northern Italy. During the 1st century, the Istrian workshops of Fažana, on the territory of Pola (Pula), and Loron, on the territory of Parentium (Poreč), were the main manufacturers. The latter were remarkable for their exceptional size and ownership history; controlled at first by aristocratic families, both workshops became part of the imperial domain under the Flavians. The history of ownership is well documented through extensive stamping of the ceramic containers.Two decades of intensive research have provided a precise picture of the trade routes of Dressel 6B amphorae. However, archaeological and epigraphic investigations alone fail to address issues regarding the actual production processes and strategies adopted in those workshops. Amphorae are thus only studied as proxies for ancient trade patterns whereas they are, first and foremost, manufactured artefacts, produced in considerable quantities and designed for a specific purpose.A significant improvement to the body of knowledge on Dressel 6B would certainly be achievable by combining already available sources of information with mineralogical and geochemical data. The present study is based on analysis of ceramic bodies from about 300 amphorae (EDXRF, petrography) and about 30 clay samples collected in the field (EDXRF, XRD). The emphasis lies on raw material collection and preparation processes and their implementation over several centuries in Istrian workshops. The results help us reconsider natural resources’ management and production strategies in large amphorae workshops over a long duration.