Fashion -perhaps the quintessential luxury industry -took a prominent place in the displays. The Exposition, extensively reported in America, threw the spotlight on the chemise and cloche, presented by designers ranging from the unknown Genevieve O'Rossen to the well-known Jean-Charles Worth, Callot Soeurs, Sonia Delaunay, and Paul Poiret, all of whom exhibited clothing in the tubular silhouette. In the end, the Exposition of 1925, instead of celebrating the advent of the overarching French style sought by artists, marked the beginning of the decline of the "moderne" or Art Deco style. The presence among the ensembles of such designers as Ruhlmann, Süe, and Mare, and Poiret's boutique Martine of several "streamlined" creations, appropriately enough, for railway cars and steamships, and of a "purist" pavilion by Le Corbusier that rejected both styles, showed the direction in which art was moving -from "moderne" ornamentation to "machine-age" simplicity to the emerging "international style" advocated by the Bauhaus and promoted in France by Le Corbusier.

During and after the Exposition of 1925, decorative artists such as Ruhlmann, Dunand, and Paul Folliot were still producing luxury "moderne" interiors and individually handcrafted objects that only the wealthy could afford; and Le Corbusier continued to criticize them for their refusal to make beautiful, functional objects that could be mass-produced by machine for the benefit of ordinary people. In 1929, this purist, anti-ornament faction withdrew from the Société des Artistes Décorateurs to form the Union des Artistes Modernes, appropriating for themselves the adjective "modern." The two distinct factions would remain in contention until the Second World War. Perhaps put off by these controversies, and having been shown the folly of political engagement in the art world by the tribulations of Paul Poiret, couturiers had less and less to do with decorative arts organizations during the 1920s, although they still responded to the same artistic trends. By 1925, with the "moderne" style reflected so beautifully in the clothing shown by couturiers at the Exposition, a simplifying, classicizing trend also became visible, together with another trend welcomed by American clients: an explosion of sportswear.

By 1921, Madeleine Vionnet's unstructured styles were making a quiet revolution with their attention to cut and simple elegance, rather than ornament. Working between 1921 and 1925 with Thayaht (the son of an Italian friend of Vionnet), who had studied under Jay Hambidge at Harvard in 1920, Vionnet collaborated on an effort to design modern clothing according to Hambidge's principles of "dynamic symmetry," a system derived from classical proportions and based on a geometrical analysis of the Parthenon. Hambidge believed that the system could be applied in any field of art to objects of any style to assure the most beautiful results [fig. 110]. The Main Gallery of the RISD Museum, designed by American architect William Aldrich, is an example of "dynamic symmetry" applied to a classical-style building [fig. 111].(34) Thayaht used the theory of "dynamic symmetry" in creating some surface designs for Vionnet, and in one dress, Vionnet experimented with actually cutting the silk according to Thayaht's ideas.

Betty Kirke believes that from that time forward, Vionnet, having assimilated the ideas of "dynamic symmetry," used them in her innovative cuts, which combined straight grain with bias to create elegantly draped clothing of superb fit that clung to the body beneath it.(35) "The couturier should be a geometrician, for the human body makes geometric figures to which the materials should correspond," Vionnet told Jacques Griffe, revealing her instinctive understanding of the importance of geometry in the design of clothing in the 1920s.(36) Vogue christened these dresses "anatomical cuts" in an article of 1925, and they were very successful in America. Vionnet's clothing based on the principles of geometry harmonized with the aesthetic of the machine, which was developing in America for everything from locomotives to decorative arts. This was also in line with what French purist artists Ozenfant and Le Corbusier were advocating, in that her dresses were classically simple, unornamented, and possessed of the shiny surface and perfect curves of the newest machines [fig. 112; compare fig. 144, p. 169]. It took an especially fine figure to wear one of these creations, and only six of Anna Tirocchi's clients tried. As usual, the chic Mrs. Byron S. (Isabel) Watson led the way by purchasing a blue velvet afternoon dress by Vionnet in 1926.