The first metaphors may, or may not, have been animal based, but materials are just as adaptable. And few are as adaptable as glass. The Glass Ceiling as the impenetrable, yet invisible boundary. The Heart of Glass as a state of extreme emotional weakness. While in most glass metaphors the focus is an inherent property of glass: transparency.
With the exhibition Welt aus Glas. Transparentes Design the Wilhelm Wagenfeld Haus Bremen abstract that metaphor to explore the link between transparency in design and architecture, and transparency in society.