WW2 isn’t my primary focus so this info is limited, but it had a big effect on stockings at least in the US. Prior to the 1940s, women regularly wore stockings. They were commonly silk which was imported from Japan until the US was unable to import silk products, when nylon stockings were used. US-based company DuPont first started producing nylon in 1935, with nylon stockings shown at the 1939 World’s Fair. In WW2, production of nylon was moved to benefit the military for parachutes. At this time, existing stockings were treasured and if a woman couldn’t get any, she would use makeup on her legs and draw “seams” up the back of her legs (sort of like fake tan today minus the line.)

Hemlines rose and simple lines were used within patterns due to rationed materials. (Meaning sleek and fitted, without additional ruffles or pleats.)

Women who worked in factories regularly wore trousers and this helped them gain acceptance for casual wear. Katharine Hepburn wore them and popularized the look.