This paper presents the results of an extensive qualitative study investigating how professional designers utilize personal idea archives. While we know that designers archive creative ideas in different formats and on different platforms, we know little about if and how designers utilize these idea archives in their daily practice. Through a series of interviews (n=20) and walkthroughs of design idea archives, we identified two archetypal strategies. The Problem Solver is concerned with the task at hand, keeps relevant ideas around, and discards them when the ideas have served their purpose. On the other hand, The Artisan Designer systematically archives potentially useful ideas in carefully selected formats and continues developing ideas over extended time spans. We conclude with a discussion about how these different strategies might be supported by technological archiving tools.