"Two women model Firestone's entrée into the world of fashion: undergarments made with Controlastic, an elastic yarn made of rubber ("Our Most Versatile Vegetable Product," said National Geographic in a February 1940 story). The tire company debuted the rubber product, no longer used in today's stretch fabrics, at the 1939-1940 World's Fair with a promise that it would fulfull 'that very much formfitting desire that is paramount today in so much of women's wear.'"
From Flashback, January 2003, National Geographic magazine