It was mere chance that Wallace Hume Carothers dicovered the Nylon fabric in 1937. DuPont already had searched for this fabric and had spent more than 27 million US dollars. Stockings made of Nylon were brought to market in 1940. They were more expensive and rough-textured than silk stockings. But the nylon stockings were advertised in a big way.
Nylon was not only an accessory but was used for parachutes as well. The stockings and tights captured the market in the end of the 1940Žs. The seamed stockings were so popular that people drew a pretend seam onto their stockings. There was no other solution for women after the War. It was different in America: the women lined up to get one of the coveted nylons. they even joined nylon clubs.

Unfortunately the inventor could not enjoy the success, he commited suicide 20 days after having applied for the patent. He did not see the potential of his new developed material. But his assistant still got the Nobel prize. Nylon was a real revolution for the entire clothing industry. It was the first time that a fabric could be manufactured independent of natural ressources. Nylons is the ancestor of technical fabrics and not only used for leg wear. It is one of the great inventions of the industrial history.
The special material properties of nylon required the further developement of the circular knitting machine. In the end of the 50Žs these were cheaper and faster than traditional Cotton machines, which produced the most high quality seamed nylons until then. It was a fast end for the seam, but there are still some fans left. Read more about sockclips or knee high.