During the last four decades, mesoamerican archaeologists regularly have employed various chemical assay techniques to determine the geological sources of obsidian artifacts. In recent years, the reliability of these analytical procedures has increased and their costs have declined, encouraging the assay of ever larger samples. Nonetheless, several constraints make it unlikely that compositional data will be used routinely to attribute entire collections to their geological sources. This report describes a test of visual sourcing, a technique that for many sites in the Maya region is only slightly less accurate than compositional assay. We also propose sampling strategies that combine visual and compositional sourcing in ways that allow large collections to be accurately sourced at low costs. Finally, we suggest ways to develop the technique for use throughout Latin America.