hen E. I. du Pont de Nemours and Co. debuted nylon, the world's first synthetic fiber, it wasn't at a scientific convention, but at the 1939 New York World's Fair. The company bragged that its new fiber was "as strong as steel," but also "as fine as a spider's web." But since the term "nylon" was never registered as an official trademark, Americans and the media quickly adapted the word as a generic synonym for any silk-like hosiery. In 1940, DuPont sold 64 million pairs of nylon stockings, snagging more than 30 percent of the hosiery market.