cut along straight lines and constructed of rectangular motifs. His styles offered structural simplicity The corseted look and formal styles of the previous period were abandoned, and fashion became more practical, and streamlined. with the use of new materials, brighter colours and printed designs. The designer Coco Chanel continued the transition, popularising the style of sporty, casual chic. Jewelry In the 1920s and 1930s, designers including René Lalique and Cartier tried to reduce the traditional dominance of diamonds by introducing more colourful gemstones, such as small emeralds, rubies and sapphires. They also placed greater emphasis on very elaborate and elegant settings, featuring less-expensive materials such as enamel, glass, horn and ivory. Diamonds themselves were cut in less traditional forms; the 1925 Exposition saw many diamonds cut in the form of tiny rods or matchsticks. The settings for diamonds also changed; More and more often jewellers used platinum instead of gold, since it was strong and flexible, and could set clusters of stones. Jewellers also began to use more dark materials, such as enamels and black onyx, which provided a higher contrast with diamonds. Jewellery became much more colourful and varied in style. Cartier and the firm of Boucheron combined diamonds with colourful other gemstones cut into the form of leaves, fruit or flowers, to make brooches, rings, earrings, clips and pendants. Far Eastern themes also became popular; plaques of jade and coral were combined with platinum and diamonds, and vanity cases, cigarette cases and powder boxes were decorated with Japanese and Chinese landscapes made with mother of pearl, enamel and lacquer. Rapidly changing fashions in clothing brought new styles of jewellery. Sleeveless dresses of the 1920s meant that arms needed decoration, and designers quickly created bracelets of gold, silver and platinum encrusted with lapis-lazuli, onyx, coral, and other colourful stones; Other bracelets were intended for the upper arms, and several bracelets were often worn at the same time. The short haircuts of women in the twenties called for elaborate deco earring designs. As women began to smoke in public, designers created very ornate cigarette cases and ivory cigarette holders. The invention of the wrist-watch before World War I inspired jewelers to create extraordinary decorated watches, encrusted with diamonds and plated with enamel, gold and silver. Pendant watches, hanging from a ribbon, also became fashionable. The established jewellery houses of Paris in the period, Cartier, Chaumet, Georges Fouquet, Mauboussin, and Van