"Prototyping Puppets" combines craft and performance in a puppet making STEM workshop for informal learning. We report on its final evaluation in two events (n=10 and n=13) to show how the design addressed black boxing of technology through a craft-centric approach and successfully engaged different student populations through an educational framing that included performance practice. The informal learning workshops are aimed at 5th grade level students. First, the problem space is laid out and the approach of the project introduced. Second, the design realization is briefly covered. Third, the final evaluation of the design in two workshop conditions is presented using qualitative as well as quantitative data. Students showed self-perceived increases particularly in their attitudes toward technology. These results are discussed before we report on the adaptation of the workshop for different conditions to illustrate the flexibility of the basic set up.