When it comes to the durability of a tennis string, it depends on what you mean by that. Above all, should it not break or should it primarily retain its playing characteristics? If you want the string to last as long as possible before it breaks, polyester and co-polyester strings clearly have the edge. If you want it to retain its playing properties for as long as possible, multifilament and natural gut strings are the better choice. In general, the thicker the string, the longer it will last.
Our recommendation:
Luxilon Adrenaline Century20