Jean Gauthier had his first workshop at 12-14 rue Jean Robert in Paris and later expended with factories in the town of Ezanville. In the early days just after the first world war Gauthier made cameo shades that were sometimes signed Gauthier. The plants in Ezanville were opened for the production of Art Deco glassware in molded-pressed glass. Many Art Deco models are unsigned. Some are signed EJG for Establishments Jean Gauthier. Others are signed J.Robert pseudonym for J. Gauthier based on the street name of the first workshop. In the 30s Gauthier started a line of shades done in opalescent semi-crystal, mainly cups. Some models are unsigned. Others are signed Ezan France, signature for Gauthier based on the city of the second plant.