The origin of Günsenin IV amphorae from the "Novy Svet Late Byzantine shipwreck" (Crimea) was investigated using chemical and petrographic analyses. Besides a main group, several small sub-groups indicate multiple workshops. The former shares similar features with examples of Günsenin I amphorae, including some from the Ganos workshops (Turkey), suggesting that the clayey material they were made of comes from the same geological formations. Petrographic analyses further narrows down the area to parts of the Dardanelles strait and of southern Thrace. These hypotheses are supported by surveys material carried out in the strait, and call for future development of field work in this area.