The invention and spread of lost-wax casting in South America is not amenable to explanations based on the concepts of practical or prestige technologies. Here we propose an alternative model to explain this phenomenon, based on a combination of technical analyses of Colombian metalwork and ethnographic information. A crucial element of our argument is that we should not focus on the cast objects or the casting process only, but rather we should consider the role of wax in this innovation. We develop the claim that the use of wax may have been culturally just as important as the metals, and that perhaps metals were used in a process of transformation that required the use of wax, as opposed to wax being simply the medium to make gold objects more beautiful. The focus on wax and its symbolic role may help explain both the invention and the adoption of the new technology, thus subsuming these two categories that those studying innovations tend to separate heuristically.