This paper focuses on the “Block-Eisenbahn” (block train), a particular work by Lyonel Feininger, one of the first masters appointed to the Bauhaus in 1919. The block train’s main characteristics are internationality, model consistency and unbreakability – and it is one example of how material and color experiences through toys were discussed in different frames of reference in the context of the Bauhaus. These works were developed, discussed and commercialized in various situations and taken seriously as learning material, but above all, they represented a design task in teaching. Feininger used the term ‘model’ when explaining his work. A model is a representation of an object and all of its physical properties, but not an exact reproduction. Through models, central features of an object are represented abstractly and perhaps even highlighted. This negotiation and upheaval of the original exemplifies how toys, if they are taken seriously and if their innovative strength is acknowledged, can serve as a starting point for educational and didactic figures of thought.