Stretch Magic™ is a strong, clear and opaque elastic cord for jewelry making, available in several different styles. It workds great with fire-polished beads! 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. All you have to do is choose the right cord for your beads' hole size and for supporting the overall weight of your project. 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, such as Hypo Cement. 1.5mm and 1.8mm cord is not recommended for knotting. To finish these sizes, use end caps.