Obsidian production was a major componente of classic period Teotihuacan´s economy, with hundreds of workshops producing cores and blades of green obsidian and bifaces of grey obsidian for distribution through out central México. Although green obsidian was evidentrly obtained through a state network, grey obsidian procurement was conducted independentrly by most workshop groups. Most production took place in residential areas beyond the major public structures of the city, but some of these craftsmen also worked periodically within the public precincts where their output would have been at the disposition of dtate officials. The burden of this levy fell primarilly upon those sectors of the industry that were most dependent on the state for support and most involved in external distribution However, despite this evidence of an important administered element in the Teotihuacan obsidian industry, the workshops apparentrly maintained their independence from the state. This may have been due to their organization in strong social units that had a long history of independent existence, and to their self-reliance in procurement and distribution during the earlier stages of the industry´s development.