In 1916 LFG introduced their Roland C.II, which used a fuselage made of "bent" plywood, forming both the external skinning as well as the main load bearing surface. This made the plane immensely strong in comparison with contemporary designs, although it was also quite heavy. Similar designs were also produced by Pfalz Flugzeugwerke, who had originally built the Roland under license.
By the late 1920s the price of aluminium (specifically duralumin) started dropping considerably and many manufacturers started using it to replace the internal framing, and in some cases, the external skin. A classic example of such a design is the Ford Trimotor, which retained the old type structure with new materials. The structure of the plane consists of a trusswork of U-shaped aluminium beams, with a thin skin of aluminium riveted on top, using skin corrugations instead of wing ribs and fuselage stringers.