FREE SHIPPING for orders over €100 within the EU 
FREE SHIPPING for orders over €100 within the EU
Most players spend weeks researching their next racquet and about 30 seconds picking a string. That's backwards. The string is the only part of your setup that comes into contact with the ball. It determines how much power you're working with, how much control you have over direction and depth, how much spin you can generate, and whether your arm holds up through a long season.
The string market is large and genuinely confusing, with hundreds of options across four main material categories. But once you understand what each category actually does on the court and why, the decision narrows quickly. This guide walks through everything, material types, string shape, gauge, tension, and hybrid setups, so you can make an informed choice rather than just copying someone else's setup.
Natural gut is the oldest string material in tennis, in use since Pierre Babolat first produced it for racquets in 1875. It is made from the serosa layer of cow intestine, a labor-intensive process that takes material from two cows to produce a single set of strings. The cost reflects that.
What natural gut does better than any other material is hold tension over time. A freshly strung set of natural gut will still feel close to its original tension after weeks of play, while most synthetic strings begin dropping tension within the first few hours on the machine. The feel on contact is also unique, soft, elastic, and responsive in a way that players consistently describe as the most direct connection to the ball of any string type.
The drawbacks are real: price, sensitivity to moisture, and relatively low durability on aggressive off-center shots. For those reasons, natural gut as a standalone string is mostly the territory of professional players and serious club players who prioritize feel above everything else. Where it appears most often today is in hybrid setups, paired with a polyester main to combine the gut's tension stability and comfort with the poly's control and spin.
Natural gut is not a category TRU PRO produces, but it's worth understanding because it's the reference point that every other string type is implicitly compared against.
Synthetic gut is nylon, typically constructed around a solid central core with one or more outer wraps. It is the most affordable category in tennis strings and has been the default setup for recreational and club players since the 1950s when synthetic manufacturing made it viable as a mass-market product.
The performance is adequate for players at the recreational level: reasonable power, acceptable comfort, and enough durability to last casual play sessions without breaking frequently. What synthetic gut cannot do is compete with multifilament or polyester strings in terms of either feel or performance at a competitive level. The tension drops faster than multifilament, the spin potential is limited, and the overall response is fairly generic.
For players just starting out or those who play infrequently, synthetic gut at a reasonable tension is a perfectly sensible choice. For anyone playing regularly at a competitive club or tournament level, there are better options in every meaningful category.
Multifilament strings are built from hundreds or thousands of individual microfibers bonded together, which is why they feel closer to natural gut than either synthetic gut or polyester can. The construction gives them a softer, more elastic response on contact, with good power and significantly better arm comfort than polyester.
Players with arm issues — tennis elbow, wrist sensitivity, shoulder problems — often gravitate toward multifilament strings because the additional elasticity reduces the shock transmitted through the frame on impact. At lower and intermediate playing levels, multifilament strings offer a level of feel and comfort that synthetic gut simply does not.
The trade-off is durability and control. Multifilament strings fray and wear faster than polyester, and they do not give advanced players the same degree of control or spin potential that shaped co-polys provide. For recreational players who are not breaking strings frequently and want maximum comfort, a quality multifilament is often the best choice.
TRU PRO's LUX SUPREME multifilament sits in this category — built for players who want arm-friendly playability with genuine performance characteristics, not just a soft string that lacks response.
Polyester strings, commonly referred to as co-polys, are the dominant string type in competitive tennis from the club level upward. They are constructed from a single monofilament of polyester, sometimes with a coating or specific cross-section shape to modify performance. The introduction of polyester strings at the professional level in the late 1990s fundamentally changed how tennis is played, enabling the spin-heavy baseline game that defines the modern era of the sport.
What polyester gives you is control and spin potential. The firm construction means the string deflects less on impact compared to softer materials, which translates into more predictable direction and depth on aggressive groundstrokes. The lower inherent power of a firm poly means players can swing harder without overhitting, and when combined with a shaped profile — hexagonal, square, pentagonal, the string generates stronger ball bite and snap-back, producing the heavy topspin that competitive players rely on.
The trade-offs are arm comfort and tension maintenance. Polyester strings lose tension faster than any other type, which is why serious players restring frequently, not when the strings break, but when they stop responding the way they should. Playing on dead poly is one of the most common causes of arm problems, because the stiff string is no longer absorbing impact effectively. A general guideline is to restring after every 10 to 15 hours of play, even if the strings look intact.
TRU PRO's string range is built around the co-poly category. Pure Rush is a six-sided co-poly designed for players who want strong spin access and reliable control with an arm-friendly character, a string that performs at the competitive level without the harshness that puts some players off polyester entirely. For players who want a firmer, more control-oriented response, Black Knight offers exceptional directional precision for players with full, fast strokes and no arm concerns.
Performance comparison
Rated 1–5 across six performance categories. Scores reflect typical behavior within each string type, not individual products.
| String type | Power | Control | Feel | Durability | Tension stability | Arm-friendly |
|---|---|---|---|---|---|---|
Natural Gut Premium / tour use | ●●●●● | ●●●●● | ●●●●● | ●●●●● | ●●●●● | ●●●●● |
Multifilament Comfort / arm-friendly | ●●●●● | ●●●●● | ●●●●● | ●●●●● | ●●●●● | ●●●●● |
Synthetic Gut Budget / recreational | ●●●●● | ●●●●● | ●●●●● | ●●●●● | ●●●●● | ●●●●● |
Polyester (Co-Poly) Control / spin / competitive | ●●●●● | ●●●●● | ●●●●● | ●●●●● | ●●●●● | ●●●●● |
Detailed breakdown
Within the polyester category, the cross-section shape of the string has a significant effect on spin and feel. Round strings produce a consistent, predictable response and slide more easily across each other during snapback, which is the mechanism by which strings generate topspin. Shaped strings, those with four, six, seven, or eight sides, have edges that grip the ball more aggressively on contact, which increases bite and can produce higher levels of spin on the same swing.
The tradeoff with sharper-edged profiles is faster wear, because the edges that grip the ball also grind against each other during play. Rounder profiles tend to last longer and work especially well as the cross string in a hybrid setup.
Ghost Wire from TRU PRO is a round co-poly designed specifically for the cross string role in a hybrid. Its smooth, round surface reduces friction against the main string, extends the life of the setup, and increases dwell time for better feel and pocketing.
Gauge refers to string thickness, measured in millimeters or by gauge number. In the gauge numbering system, higher numbers indicate thinner strings — 18 gauge is thinner than 15 gauge. The millimeter measurement is more reliable since gauge designations are not always consistent across manufacturers.
Thinner strings, generally in the 1.15mm to 1.25mm range, offer more power, more spin, and more feel. The string bites the ball more easily and deflects more on impact. The downside is reduced durability. Thinner strings break faster, particularly for aggressive players who generate a lot of topspin.
Thicker strings, in the 1.27mm to 1.35mm range, last longer and provide more control on big swings. They feel slightly stiffer and produce less free spin, but for players who break strings frequently, moving up in gauge is often the first adjustment worth making before spending more on premium string sets.
Most competitive players settle between 1.20mm and 1.28mm, which offers a practical balance of performance and durability. If you are unsure where to start, 1.25mm is a safe midpoint for most playing styles in the intermediate to advanced range.
Tension is measured in pounds or kilograms and describes how tightly the string is pulled through the racquet frame during stringing. Every racquet has a recommended tension range printed on the throat, and staying within that range is important both for performance and for frame integrity.
Higher tension produces a firmer stringbed with more control and less power. The ball spends less time in contact with the strings, which reduces the trampoline effect and gives aggressive players more confidence to swing fully without overhitting.
Lower tension produces a softer, more elastic stringbed with more power and a longer dwell time. The ball sits on the strings for a fraction longer before release, which generates more spin potential and a more comfortable impact feel. This is why most polyester users string at lower tensions than they would with multifilament or natural gut — the firmer material of the poly already provides the control, and lowering the tension adds back some comfort and spin access.
A practical starting point for co-poly strings is around 45 to 52 pounds, then adjusted up or down based on how the setup feels. Players who want more control can go slightly higher. Players with arm sensitivity should go lower rather than compromise on string type.
One important note: tension begins dropping the moment stringing is complete. By the time you pick up the racquet the next day, a meaningful portion of the initial tension is already gone. This is normal, but it reinforces why restringing frequency matters. Playing on a setup that has been in the frame for three months at an initial tension of 50 pounds is no longer a 50-pound setup.
A hybrid string setup uses two different strings in the same racket — typically one type for the mains (the vertical strings) and a different type for the crosses (horizontal). This isn't just a choice for professional players; it’s a practical option for any competitive player looking to combine the benefits of different materials.
The most common setup at the tour level pairs natural gut in the mains with polyester in the crosses. The gut offers tension stability, comfort, and feel, while the polyester cross adds durability and some control. Roger Federer used this setup for most of his career.
For players wanting to soften a firm polyester setup without changing their main string, using a softer round co-poly or a multifilament in the crosses is an effective adjustment. The cross string mainly supports the interaction, but it significantly impacts the overall feel and arm comfort.
Ghost Wire works well in this role — its smooth, round surface complements a shaped main like Pure Rush by increasing pocketing and softening the response without reducing spin or directional control. Players who have tried this combination often report it as one of the best value-for-money hybrid setups available.
The decision comes down to playing level, style, and physical situation.
If you play recreationally and are not breaking strings, a good multifilament at mid-range tension gives you comfort and power without complexity.
If you are playing competitive club or tournament tennis and generating your own pace, a co-poly in the 1.20 to 1.28mm range at 45 to 52 pounds is almost certainly the right starting category. From there, the choice between a softer, more elastic poly and a firmer, more control-oriented one depends on your swing speed, your arm tolerance, and the frame you are playing with.
If you have arm sensitivity but want the control of polyester, two options help: a softer poly formulation like Pure Rush, strung at the lower end of the tension range, or a hybrid setup pairing poly mains with a softer cross.
If you are not sure where to start with TRU PRO strings specifically, the String Selector Tool walks through your playing situation and returns a recommendation based on the characteristics above. The Demo Package is also worth considering if you want to test multiple strings before committing to a reel.
For more on string decisions at the competitive level, see the TRU PRO Tennis String Guide — covering comparisons, tension guides, lab data, and more.
Please complete your information below to login.