Chairs take the most stress on their back legs, where they bear the weight of the user's upper body. The engineer and designer Jean Prouvé illustrated this simple insight in his distinctive design for the Standard chair: while steel tubing suffices for the front legs, since they bear a relatively light load, the back legs are made of voluminous hollow sections that transfer the primary stress to the floor. Standard is offered with a seat and backrest in wood or as the model Standard SP in ASA plastic. In addition, there is the all-wood Chaise Tout Bois, whose design is very similar to the Standard chair. During World War II, Jean Prouvé responded to the limited supply of metal with a version made entirely out of veneer and solid wood.