Put a sturdy foundation into your designs with Stretch Magic. Stretch Magic is an extremely strong yet elegant and stretchy cord. The secret is a high-tech polymer that does not crack or become hard over time. Because the ends do not fray, it is easy to string. Stretch the cord before adding beads to prevent your designs from stretching out later. This cord is easy to knot, too. Just use a series of three square knots. To secure knots, use a flexible adhesive.