Artifacts from an obsidian-blade workshop dump from Ojo de Agua, Chiapas, Mexico, are analyzed to determine levels of craftsmanship and craft specialization. Detailed consideration of knapping errors and rejuvenation flakes reveals that the blademaker at Ojo de Agua was moderately skilled at his craft, which he practiced on a part-time basis. The maximum level of output from his workshop was 26,000, or fewer, fine blades per year, or the equivalent of part-time work during a three-month period. Analysis of knapping strategies evident in the workshop debris suggests that the blademaker's overriding strategy was to achieve a balance between effort and knapping risk at the expense of raw material. Access to obsidian cores does not appear to have been a concern, as little effort was made to economize in this respect, and thousands of usable, irregular blades were discarded in the workshop refuse.