The title of this presentation could mediate the impression as if there is no finer challenge for the design engineer, than using combined materials for his constructions. On the contrary, for a designer thinking in functions the choice of the material is actually contrarious, because his ambition is basically to fulfill the desired properties of a product. The choice of a new material means for him that the well known materials – that he likes to use because of its well known properties like their behavior in the manufacturing process – do not fulfill any demands on my new idea of construction. From this a first thesis for this presentation can be deduced: From the designer’s point of view, choosing a material represents a restriction that has nothing to do with the creative process of product development.