Collections of bullae, found in deposits are known to have been indeed stored in archives. The impressions of Sasanian seals, preserved on clay bullae suggest that the seals functioned as validation of documents as as guarantees of exchanged goods and services both in an administrative context and in private society. Sasanian bullae such as the one here illustrated have a convex face and a relatively flat back with, sometimes, traces of perforations or grooves left the strings that attached the bulla to the sealed object.

Administrative bullae were generally un-iconic and exclusively epigraphic, giving the names of administrative provinces and the titles of offices such as those of finance and justice, both posts held by the Zoroastrian clergy. On the other hand, those bullae used for royals and important functionaries generally bear the owner’s bust accompanied by an inscription giving the name and title. Private seals and impressions, distinguished by a single motif sometimes accompanied by an inscription, provide a rich variety of iconographic patterns, largely reflecting the contemporary cultural and religious traditions of Iran, though only indirectly explained by the inscriptions accompany them.