The strings are the life and soul of the racket. However, for most people, racket strings are just an afterthought. There are now hundreds of strings available on the market, so how do you decide which ones to go for? Over the years, strings have evolved from natural gut via synthetic gut and multi-filaments to the latest polyester strings.
There is alwavs a compromise between playability and durability, with natural gut and multifilament strings being the most playable and Poly strings being the most durable. This has led to the current fashion for combining different strings on the mains (vertical) and crosses (horizontal). The classic example of this is Roger Federer, whose Champions Choice strings consist of a strong poly and natural gut. Rafa Nadal uses a soft poly string all round (Babolat RPM Blast).
Generally speaking, thinner strings offer improved playability while thicker strings offer enhanced durability.
Tennis string gauges range from 15 (thickest) to 19 (thinnest), with half-gauges identified with an L (15L, 16L, etc), which is short for “light”. Obviously, the thinner the gauge, the more powerful the string, with lots of spin potential. BUT the string will be less durable, but you could allow for that by going for a really thin, durable string.
Each racket has its own tension range (shown in the technical spec of each racket). The optimum tension for the majority of people is mid-tension. We would recommend picking a tension 1 or 2 lbs more than mid, as rackets lose tension fairly quickly.
Generally speaking, the higher the tension, you get more control but less power. The lower the tension, you get more power but less control.