Rotoreliefs were the next phase of Duchamp's spinning works. To make the optical "play toys", he painted designs on flat cardboard circles and spun them on a phonographic turntable. When spinning, the flat disks appeared three-dimensional. He had a printer produce 500 sets of six of the designs, and set up a booth at a 1935 Paris inventors' show to sell them. The venture was a financial disaster, but some optical scientists thought they might be of use in restoring three-dimensional stereoscopic sight to people who have lost vision in one eye. In collaboration with Man Ray and Marc Allégret, Duchamp filmed early versions of the Rotoreliefs, and they named the film Anémic Cinéma (1926). Later, in Alexander Calder's studio in 1931, while looking at the sculptor's kinetic works, Duchamp suggested that these should be called mobiles. Calder agreed to use this novel term in his upcoming show. To this day, sculptures of this type are called "mobiles".
Rotoreliefs were the next phase of Duchamp's spinning works. To make the optical "play toys", he painted designs on flat cardboard circles and spun them on a phonographic turntable. When spinning, the flat disks appeared three-dimensional. He had a printer produce 500 sets of six of the designs, and set up a booth at a 1935 Paris inventors' show to sell them. The venture was a financial disaster, but some optical scientists thought they might be of use in restoring three-dimensional stereoscopic sight to people who have lost vision in one eye. In collaboration with Man Ray and Marc Allégret, Duchamp filmed early versions of the Rotoreliefs, and they named the film Anémic Cinéma (1926). Later, in Alexander Calder's studio in 1931, while looking at the sculptor's kinetic works, Duchamp suggested that these should be called mobiles. Calder agreed to use this novel term in his upcoming show. To this day, sculptures of this type are called "mobiles".