A catalogue documenting two exhibitions of works by Alexander Calder and Jean Prouve at Gagosian Gallery, Paris, and Galerie Patrick Seguin, Paris. Calder and Prouve met in the early 1950s. They corresponded regularly between Calder’s frequent trips to Paris, exchanging ideas on architecture and sculpture. In 1958, Calder collaborated with Prouve to construct the steel base of La Spirale, a monumental mobile for the UNESCO site in Paris. Letters between the two are illustrated and reprinted in the catalogue. Calder/Prouve evokes comparisons in the broad, expressive range of production, emphasis on form, and use of new technologies that the close friends and collaborators evinced in their parallel practices as artist and designer. Considered together, the works in this book testify to the fruitful exchange between two giants of modernism in its most utopian aspirations. Calder works in the book include mobiles, stabiles, and a suite of thirty little-known animal drawings, while Prouve is represented by rare examples of furniture and architecture including two prefabricated structures. Calder’s invention of the mobile resonated with both early Conceptual and Constructivist art as well as the language of early abstract painting. Prouve is widely acknowledged as one of the twentieth century’s most influential industrial designers, with a wide-ranging oeuvre that brought a strong social conscience to bold elegant design within an economy of means. Never-before-published letters between Calder and Prouve are illustarted and reprinted in the catalogue.