There is stretch and there is creep. Stretch is the elongation of a string, when shooting, that rebounds back to it' s original size. Creep is the permanent lenthening of the string. It happens for two reasons. When a string stretches and doesn' t rebound, that is creep, or when a string is tied poorly and the strands move, that can also result in creep.

String materials such as 8125 and D75 are products that stretch a bit and creep a bit. Pre-stretching, like Winner' s Choice and many other custom string builders do, will take care of most of this creeping problem with this material. The natural stretch in this material combined with it' s small diameter allow strings made from it, to be a fraction faster.

String materials like 450 plus or Ultra Cam are products that are blended with vectran, which resists stretching and creeping, more than other string materials. Ultracam contains the highest percentage of vectran, and therefore stretches and creeps the least. These materials are still prone to creep from a poorly tied string.

As a note: There are many sources of properly made strings that will stretch or creep very little. I make my own, and don' t think Winners Choice strings are as good.