Abstract: A method of manufacturing a retro-reflective shell having a curved or irregular surface for reflecting light in all directions from a laminated product, comprising a substantially flat sheet of a plastic material and a reflective layer on at least one side of said flat sheet plastic material. The reflective layer comprises a transparent adhesive substance and transparent glass or plastic pearls with a diameter between 0.01 and 0.05 mm. The substance adheres to the flat sheet plastic material, to form the laminated product. The product is heated to a thermo-vacuum-forming temperature, whereupon the product is vacuum-formed on a mould having the desired curved or irregular surface shape, in order to form a shell.