In a collaboration between experimental physicists and theoretical physicists in the framework of the Dynamics and Topology (TopDyn) excellence project, a system of many small magnetic whirls could be engineered to form a regularly ordered state. Such a transition from a disordered to an ordered phase is analogous to the well-known crystallization, which, however, occurs here in two dimensions. For the research work at Johannes Gutenberg University Mainz (JGU), experimental physicists around Professor Mathias Kläui cooperated with a group of theoretical physicists around Dr. Peter Virnau. The results have been published recently in the journal Advanced Functional Materials. The TopDyn research center is funded by the German federal state of Rhineland-Palatinate.