The Weco Products toothbrush was made with EXTON, a synthetic nylon (petroleum-based product) developed by DuPont chemists. Weco sold their toothbrushes for 50 cents each in 1938 and just a year later, Johnson & Johnson introduced a competing nylon-bristle toothbrush. Nylon was the world’s first synthetic fiber discovered by Wallace Carothers, a Harvard professor working in the research laboratories at DuPont after experimenting with artificial materials for over six years. He also discovered neoprene rubber (wetsuits) and did important work with polymers.
Nylon usage expanded quickly and DuPont soon created one of the biggest money-makers in company history, nylon stockings for women. Soon, the applications for nylon became widespread, being utilized in not only toothbrushes and hosiery, but also in fishing lines, luggage, lingerie, surgical thread, parachutes and more. It launched a whole new era of synthetics. You can read more about the petroleum product nylon on the American Oil & Gas Historical Society website.