Wartime production during World War II required vast amounts of cotton, silk, nylon, wool, leather, and rubber. In 1942, the United States War Production Board issued Regulation L-85, cutting the use of natural fibers in clothing and mandating a 10% reduction in the amount of fabric in women's beachwear.1940s bathing suits, like many other clothing items, was also losing its modesty. The '40s was the era when the midriff was born, and it was shown in swimsuits as well as playsuits. 1940s swimsuits were tight, unlike the suits of previous eras.One-piece swimsuits were still popular, but the new two-piece suit had plenty of fans too. The materials used to make swimsuits today were not invented yet, so suits were made from rayon jersey and rayon jersey blends with knit cotton linings. Many suits had accent panels of a velvet like rayon velour. Some also featured ruching on the front or side panels that were both pretty and figure flattering.These wonderful color images of 1940s swimwear really evoke the glamour of that period.(Photos by Charles W. Cushman