<p>A foldable composite panel (1) comprising an inner layer (2) formed from a first material having a relatively high plasticity at least in compression, bonded to at least one adjacent outer layer (3) formed from a second material having a relatively low plasticity. The composite panel (1) can be permanently folded without failure at ambient temperature through an angle substantially greater than that through which the outer layer (3) alone could be folded without failure under comparable conditions.</p>