The variety of synthetic fibres used in manufacturing fibre grew steadily throughout the 20th century. In the 1920s, acetate was invented; in the 1940s, acetate, modacrylic, metal fibres, and saran were developed; acrylic, polyester, and spandex were introduced in the 1950s. Polyester became hugely popular in the apparel market, and by the late 1970s, more polyester was sold in the United States than cotton.[18]
By the early 20th century, the industry in the developed world often involved immigrants in "sweat shops", which were usually legal but were sometimes illegally operated. They employed people in crowded conditions, working manual sewing machines, and being paid less than a living wage. This trend worsened due to attempts to protect existing industries which were being challenged by developing countries in South East Asia, the Indian subcontinent and Central America. Although globalization saw the manufacturing largely outsourced to overseas labor markets, there has been a trend for the areas historically associated with the trade to shift focus to the more white collar associated industries of fashion design, fashion modeling and retail. Areas historically involved heavily in the "rag trade" include London and Milan in Europe, and the SoHo district in New York City.
By the late 1980s, the apparel segment was no longer the largest