Makerspaces are an emerging tool in the engineering education field. Compared to the current standard of formal, class-based education, makerspaces provide a multitude of resources meant to support students through more informal, project-based learning. This study is part of a larger project exploring supporting design learning through design decision making. Here we investigate how students make material decisions when pursuing projects in a university makerspace. What kinds of questions, options, and criteria do they explore, and what rationale do they use to make their final choice? How does this change in time, across different projects, and across different students? In previous work, 7 undergraduate students completed a self-driven project while documenting their process and anything else they felt was relevant. During this study, 6 researchers analyzed written traces of the students’ project progress. Material and tool decisions were identified, and coded to present questions, options, and criteria over time using the Design Space Analysis framework. Trends were identified across students, time, and different materials or tools. Through our analysis, we discovered the following results. Though students are pursuing different projects, they all deal with similar decisions around material and tool choice during their processes. For most decisions, students consider very few options, although there are some where more are contemplated. Regarding criteria, students consider cost, aesthetics, and availability, but often not specific functionality requirements. Students naturally provide design rationale as part of their process, but it is not very well developed. The results from this study will allow us to gain greater understanding on what students tend to consider, and develop methodology to make a greater number of potential options more visible to students during their project processes.