Sandwich panels are a building system that consists of an outer skin, a core and an inner skin. Architects have used sandwich panels to create a high-tech or industrial appearance, for example in the Sainsbury Centre for Visual Arts (1978, Norwich) by Norman Foster. Restoration of this construction system is important for safeguarding these buildings. The sandwich panel was developed by Jean Prouvé around the Second World War. The panels have been produced on a commercial scale since the 1960s. Initially, sandwich panels were produced using steel skins, but later also materials like aluminium, glass-reinforced polyester, PVC, asbestos and precast concrete were used.