The designers involved in the costuming for the Théâtre read like a who's who of Paris couture of the time, or a near who's who. Notably absent is Coco Chanel, who had closed up shop in 1939, believing that war was no time for fashion.
It was indeed a very challenging time for French fashion. After the Nazi occupation, raw materials, energy and transportation were at a minimum. In 1940 German officers seized the entire archives of the Chambre Syndicale de la Couture. Balenciega and Grès were shut down on the grounds that they had used more than their allotment of fabric. Balenciaga reopened with the intervention of the Spanish Embassy, while Madame Grès had to quit making her iconic draped designs.
The German Reich was planning to uproot French haute couture, making it part of its regime, with headquarters in Berlin and Vienna. By 1944, the Nazis threatened to shut down the haute couture completely. It was only saved from extinction by the Liberation.
Remarkably, during the four year occupation the majority of haute couture designers had managed to remain in business, maintaining their creativity and keeping their skilled workers. When the Liberation came, the industry was prepared for its rebirth.
Prints came back in the form of polka dots, stripes, plaids, checks and historic patterns derived from Chinese vases, Delft earthenware and Renaissance velvet. Draped designs were also back, emphasizing necklines and hips. Small waists were emphasized with the V-line (for Victory). Jackets softened, hems lengthened, colors and elaborate decoration returned.
Some of the designers involved with the Théâtre were especially important prior to the 40s (Schiaparelli comes to mind first) while some younger designers were rising stars, important at and after the New Look transition.
Dior was part of the firm of Lucien Lelong from 1941 until December 1946. According to Nadine Gasc ("Haute Couture and Fashion 1939-46," one of the essays collected in the book Théâtre de la Mode), there is little doubt that Dior was responsible for a turquoise chiffon dress with white polka dots, with its low neckline and emphasis on the waist. The only difference between this and his New Look style of 1947 is the length.
Jacques Fath, among others, showed a pen silhouette.
List of the design houses contributing to the Théâtre de la Mode
Ana de Pombo
Henry à la Pensée
Madeleine de Rauch
Martial & Armand