We used participatory design (PD) as a way to fully incorporate the voice of children in the development of children’s library programming. Using KidsTeam-UW as a model, we worked for ten weeks with a group of eight 6-9 year-old children, focusing on a different aspect of 3D printing each week. Data in the form of session notes, photos, and video recordings were analyzed to determine important elements and best practices for a printing program, as well as guidelines for librarians to incorporate the practice of PD in their own program development.