Castiglioni investigates on the combination of materials with different geometry and rigidity characteristics to design Rosacamuna, a foldable chair produced by Zanotta. Over the main skeleton, a single metal tube bent to form the front legs and backrest, comes hinged a system of flat struts. These simplify the design of the hinges and make the folding mechanism safe and easy – the seat tilts up and the front legs fold flat with the back ones -, as to prevent accidental closing. Other tubes, thinner, brace the transversal structure, providing the supports for the comfortable rounded seat in nylon coated with leather.