I get all the strings for my shop from Tailormade (734-246-3182).They make a string called a Tux which has the tightest servings I have ever used. Even the bottom of the yoke cables on single cam bows are not seperating. We primarily use 450+ material for its extreme durability but he stocks all types of materials. Prices are really reasonable too. The owners name is Marv and he is always happy to answer any questions.