Pre-stretching originated at a time when natural gut strings were not produced as perfectly as they are today. Due to the short pre-stretching with increased force, the natural fibers of the gut string were able to fit together more firmly and the desired tension was retained for longer. Even if natural gut strings are produced more stably today and are additionally plasticized, most stringers still recommend the use of pre-stretch for this type of string.
In the case of synthetic strings, however, the effect of pre-stretch is very controversial. We do not recommend this with monofilament strings. And for multifilament strings, too, our measurements have so far not been able to confirm that the ordered tension is retained longer thanks to pre-stretch.
The disadvantage, however, remains that the elasticity (“freshness”) of synthetic strings is reduced from the start by pre-stretching.
Tip: If you normally string with 10% pre-stretch, try alternatively to string without pre-stretch – but with 5% higher tension than usual.