Building on the seminal work of Thomas J. Allen, we contribute to the emerging microlevel theory of knowledge recombination by examining how individual-level characteristics of inventors affect the breadth of their technological recombinations. Our data set combines information from 30,550 European patents with matched survey data obtained from 1,880 inventors. The analysis supports the view that inventors with a scientific education are more likely to generate patents that span technological boundaries (in our case, 30 broad, top-level technological domains) than inventors with an engineering degree. A doctoral degree is associated with increased recombination breadth for all groups of inventors. The breadth of an inventor's technological recombinations diminishes with increasing temporal distance to his education, but the differences between scientists and engineers persist over time. Our findings provide several new insights for research on inventors, the literature on organizational learning and innovation, and strategy research.