Julian Hill discovered that one polyester he had made, called polyester 3-16 could be drawn into strong fibers. What is more, he discovered an unusual property these fibers had: pulling on the fibers made them stronger. The stress of drawing aligned the long, chainlike polyester macromolecules, making them very strong. This process is called cold-drawing.

Word of this discovery spread. Newspapers reported that chemists had discovered synthetic silk. But the hype was premature. At first the new polyesters showed potential as a silk replacement, However, although its fibers were strong, polyester 3-16 melted at low temperatures. This meant fabrics made from it couldn't be ironed. It also dissolved in common solvents, including dry cleaning solvents.

DuPont had been interested in a synthetic replacement for silk for a long time. In 1930 Elmer K. Bolton became the director of Central Research at DuPont. Ever pragmatic, he wanted Carothers and his team to produce discoveries that DuPont could turn into useful products. Specifically, Bolton pushed for more research into synthetic fibers.

By 1930 the economic turmoil that gripped the rest of the world had reached the United States. The Great Depression had begun in 1929 and DuPont no longer had money to spend on fundamental reserach. If they wanted to keep their jobs, Carothers and his scientists had to produce discoveries that DuPont could easily turn into profitable products. The prospect of a good synthetic fiber would become the justification for the existence of "Purity Hall".

But it was still just a prospect. Polyester 3-16 was interesting but not useful. This made Carothers turn to another sort of polymer. When he had been researching step-growth polymerization, his team had made a great many different types of polymers. The failure of polyester 3-16 to be a useful fiber made Carothers nearly abandon the idea of making a synthetic fiber. But the pragmatic Bolton was not ready to give up so easily. He urged Carothers to take another look at a family of polymers his team had made long ago and had almost forgotten, polyamides.