Carved stucco is the architectural revetment medium par excellence in Iran; its history began in Achaemenid, Parthian and Sasanian times, gained paramount significance in the Early Islamic, Seljuq and Ilkhanid periods and experienced a revival under the Safavids and Qajars. However, divides between pre-Islamic and Islamic archaeology, dynastic divisions and the Mongol conquest theory distort this trajectory. This study of c. fifty Ilkhanid stucco repertoires proposes a taxonomy of Ilkhanid stucco artistic techniques, based on the scrutiny of production technology, polychromy, inscriptions and ornamentation. It sheds light on the transfer of stucco production knowledge between pre-Ilkhanid and Ilkhanid periods. Ilkhanid craftsmen inherited millenary stucco craftsmanship practices, to which they contributed technical and artistic innovations: new artistic techniques, polychromy development, modified aesthetics, and new epigraphic and ornamental vocabulary. These finds enhance our understanding of Iranian stuccos.