The gap between "techie" and "technophobe" can be hard to bridge when training K-12 teachers. The right kind of professional development can inspire more educators to begin 3D printing in their classrooms. The wrong kind of professional development can intimidate, confuse, and, worst of all, discourage teachers from introducing 3D printing to their students. In this session, we will explore a variety of methods for effectively reaching classroom teachers who are unfamiliar with 3D printing. We will also learn how to avoid pitfalls like overuse of technical jargon and the curse of knowledge.