In the 1930s, silk was the preferred material for women’s stockings. But they were expensive and not very durable. When DuPont began manufacturing nylon in 1939, most American women switched from silk to nylon stockings.

High demand brought shortages in 1942 after the United States joined the war. Because nylon used in the manufacture of parachutes, tents, ropes, and tires, was critical to the war effort, worn-out nylon stockings were collected and recycled for military use and many women began applying a foundation on their legs ( liquid stockings) to give the illusion of hosiery. 

Nylon stockings survived for another two decades after the war, then virtually disappeared when DuPont invented stretch-fit Lycra, and pantyhose came into fashion.