The group of the Sasanian rock reliefs is one of the most important documents to understand the ideology of the Sasanian dynasty of Iran (from the 3rd to the 7th century AD) because the main role is played by the king, represented in various actions: investiture, or gift of the khwarrah by a deity; homage to the king by the family and dignitaries; king and his entourage; victory and triumph over the king's enemies; individual equestrian battles. Initially, scholars were mainly interested in the interpretation of the motifs represented and the identification of the characters who animated the scenes, based on the comparison with the monetary portraits, identified by a legend. Moreover, the figurative language of the reliefs is not entirely clear, and sometimes it is quite difficult to interpret complex scenes safely. The codes, expressed by the postures, gestures, hairstyles and attributes of the characters, which were clear to contemporaries, often appear enigmatic to us. However, the purpose of this work is not to discuss the different interpretations proposed for the iconographic motifs, but to study the theme of the birth and development of this or these craft traditions, with a methodology that starts from the assumption that the complex technical aspects underlying their production characterize the works of art in relation to the skills shared by the craftsmen of the different «production centers»: they are linked to a school that keeps a certain tradition alive, with a slow evolution, on which, however, an external agent can act quickly.