The specification discloses a method of forming a self sustained cladding panel 10 for use in a cladding panel system for a building using a resilient metal or metal alloy sheet material. The panels have a central visible portion 12 and longitudinally extending side edges 14, 16. The central visible portion has, in its relaxed state, a shape which is significantly different from the intended final shape and the panel is subsequently formed so that its central visible portion is resiliently formed into the final shape, with a resilient deformation taking place within the elastic range of the sheet material. The panel is then retained in this final shape by interconnecting the longitudinally extending side edges 14, 16 either continuously or by spaced elements such as clips.