Wedge shoes were introduced to the world by Italian designer Salvatore Ferragamo in the 1930s. He used cork and wood in his designs due to a leather and rubber shortage; since it was lighter but still sturdy and durable, cork emerged as the preferred material over wood. Wedges were also worn by women in the United States during World War II because they offered height and were more practical to walk in than high heels. Again, wedges were more readily available because they were made of cork; both leather and rubber were rationed for the war effort. Wedges took the fashion world by storm once more in the 1970s, when they were worn by men as well as women. Designs in the 1970s were much "louder" and more colorful than previous versions. Wedges made yet another comeback in the 1990s in the form of wedge sneakers. The shoe style first appeared at raves and later gained many famous fans, such as the members of the Spice Girls. Wedge sandals became a trend around 2006 and are still often worn today as a more comfortable and supportive alternative to heels.