Makerspaces have spread to libraries in recent years, to promote equitable access to technologies, expand services, and encourage participation and learning. In this paper, scaffolding of learning is studied from the perspective of library makerspace practitioners. On the basis of interviews in six Danish libraries, we analyze formal, non-formal, and informal activities and identify seven ways of scaffolding. Three challenges are discussed: (a) fostering community while ensuring inclusion in informal activities, (b) avoiding to stifle creativity in short-term activities, and (c) finding the role of the library in formal activities. We propose actions to overcome these challenges, such as encouraging scaffolds across formal, non-formal and informal learning activities and addressing the educational role of the library.