All About Strings & Stringing

"Strings are the Soul of a Racquet" --author unknown

Strings may be the soul of racquet, but to many players they are just an afterthought. Players will spend months demoing racquets yet only minutes choosing a string, the very thing which makes contact with the ball and greatly determines what the player feels. Fortunately, the non-gut synthetic string universe (mostly nylon and poly based) has improved dramatically over the last few decades. Today, there is so much diversity in the string market that any player, with a little research, can zero-in on a desired feature set. Here are a few guidelines to make your string and tension selection easier.


It's very difficult to obtain consensus on what makes a string playable. Some players like a crisp, firm playing string while others equate playability with softness and comfort. Historically, a playable string is one that is gut-like in its feel and resilience. Natural gut is the only string made from a natural product, thin ribbons made from beef intestines, which, when twisted into a tennis string, create a comfortably crisp feel that is simply unmatched. Natural Gut is the oldest tennis string and remains the benchmark for playability. While no other string material can quite match the sublime feel and response of natural gut, Tennis Warehouse offers many synthetic strings that have phenomenal playability: Babolat X-Cel, Dunlop Silk, Gamma Professional, Prince Premier Power, Tecnifibre NRG2, Tecnifibre X-One Bi-Phase and Wilson NXT. Strings that offer good playability at a lower price (below $8.00) include: Alpha Gut 2000, Head RIP Control, Head FiberGEL Power, and Tecnifibre E-Matrix (TW Exclusive).


As with our beer, most of us want a string that offers everything. Unfortunately, increased durability in tennis strings is usually at the expense of playability, especially on shorter strokes which feel stiff and dead. Thicker gauges and abrasion resistant materials will be more durable, but they are less elastic and resilient than their thinner counterparts. (See gauge table below.) If a player is breaking a 16 gauge nylon string (synthetic gut), we might suggest they switch to a 15L version of that same string, if available. For the multifilament player (who needs a softer feel), Prince has some "comfort strings" in thicker gauges, like Premier Touch 15L and Premier Control 15 . Otherwise, the next step would be a nylon durability string, such as Gosen AK Pro CX, Gamma Marathon DPC or Wilson Synthetic DuraMax. After that, we recommend trying a polyester hybrid like Volkl Psycho. If you're sawing through your crosses, we recommend a full stringbed of polyester where you can select a firm one like Kirschbaum Super Smash or a softer one like Polyfibre TCS. Finally, for the advanced (5.0+) player who blows through the strings listed above, we suggest a Kevlar hybrid, which is the end of the road for chronic string breakers. Proceed with caution as Kevlar sends a lot of shock to the tendons.

String Gauge

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". A 15L string is thinner than a 15 gauge but thicker than a 16 gauge string. Thinner strings also provide more spin potential by allowing the strings to embed into the ball more.

String Gauges and Diameters in millimeters

15 = 1.41-1.49 mm 17 = 1.20-1.24 mm
15L = 1.34-1.40 mm 17L = 1.16-1.20 mm
16 = 1.26-1.33 mm 18 = 1.10-1.16 mm
16L = 1.22-1.26 mm 19 = 1.00-1.10 mm


Nylon - synthetic gut or nylon? Truth be told, most synthetic guts are made with nylon (sometimes referred to as polyamides). There are different grades of nylon, with varying levels of feel, so don't be afraid to try different synthetic guts until you find the right fit. All in all, synthetic gut delivers a good combination of playability and durability at a great price. In the old days (wood racquet era), any self-respecting player used natural gut. Today, an impressive number of non-professional players use nylon-based strings, which have greatly improved in the feel department. In fact, Nylon multifilaments offer truly impressive comfort and power. Unlike the more basic synthetic guts (which have a single, solid core), multifilaments are comprised of hundreds or thousands of ultra pliable, elbow-friendly fibers, and bundled together with flexible resins like polyurethane. Other string materials include:

Natural Gut - the ultimate in playability, feel and tension maintenance. Often overlooked due to it's cost, natural gut is the best choice for players with arm problems or those who crave its sublime, comfortably crisp feel. Formerly, the number one choice of ATP and WTA tour players. Now used more in hybrids, combining polyester mains with natural gut crosses (with some players using gut in the mains for more power and feel). Natural gut offers maximum feel and control due to its ultra low stiffness, which provides phenomenal ball "pocketing".

Polyester- a very durable string designed to provide control and durability to players with long, fast strokes. Polyester is the number one choice on the pro tour because it allows advanced ball strikers to maintain surgical control on their fastest, most aggressive strokes. The incredible stroke speed enabled by polyester also translated into categorically higher level of spin, which literally changed the trajectories and angles available to the player. Polyester also served to harness the immense power that came with graphite era. While it used to be too stiff and dead for recreational players, a growing number of string manufacturers have devoted the lion's share of their R&D to creating softer, more elastic polys so that a wider cross section of players can enjoy its benefits. Another way to get the benefits of polyester is through a hybrid, also very popular on the pro tour. This is typically done by combining polyester (usually in the mains) with natural gut or multifilament crosses. This setup provides the durability, control and spin of polyester with the comfort, power and touch of a softer string - otherwise known as the best of both worlds. Due to its high stiffness and relatively low power, polyester is not recommended for beginners or players with arm injuries.

Kevlar - The most durable string available. Kevlar is very stiff and strings up very tight. Therefore, it is usually combined with a soft nylon cross to reduce stringbed stiffness. Ultimately, Kevlar hybrids are the least powerful and least comfortable strings currently available. Players trying kevlar hybrids for the first time (from nylon strings) are recommended to reduce tension by 10% to compensate for the added stiffness. Not recommended for beginners or players with arm injuries.

String Construction

Here's a list of string constructions, general descriptions of their associated performance benefits and examples of each:

Solid Core with One Outer Wrap

Most popular nylon string construction - majority of "synthetic gut" strings are solid core/single wrap. Main benefits are tension maintenance and crisp feel. Quality of nylon center core, as well as size and orientation of outer wraps can influence feel and comfort.

Babolat Synthetic Gut
Dunlop S-Gut
Gamma Synthetic Gut (standard or w/wearguard)
Gosen OG Sheep Micro
Prince Synthetic Gut (Original or w/Duraflex)
Wilson Synthetic Gut Control

Solid Core with Multi Wraps

Provides additional durability and cushioning.

Gamma Gut 2,
Gamma TNT Pro Plus
Pacific Powerline
Pacific Premium Power X

Multifilament (no wraps)

Bundles of micro synthetic fibers are twisted together, similar to natural gut. Nylon multifilaments are typically more comfortable than solid core strings due to the cushioning effect of hundreds or even thousands of micro fibers. Resultant effect is a soft and comfortable string, recommended for players suffering from arm problems who don't want to pay the high price for natural gut. Normal use causes multifilament strings to fray, like gut, which can be alarming to players switching from solid core strings. With the exception of braided Kevlar and polyester multis, multifilament strings are generally classified as "soft" strings.

Babolat X-Cel Premium
Dunlop Silk
Head Fiber Gel
KLIP Excellerator
Prince Premier Power
Tecnifibre NRG2, X-One BiPhase
Wilson NXT
Isospeed Control/Profession (polyolefin ribbons, very soft)
Tecnifibre X-Code (polyester filaments, very firm)

Multicore with Wraps

Smaller multifilament core with one or more outer multifilament wraps. Offers similar comfort benefits to multifilament strings with added durability.

Gamma TNT2 Tour
Gamma Live Wire
Head RIP Control


Textured strings can be found in the nylon and polyester universes, giving all ability levels a way to get a little extra grip on the ball. Nylon or synthetic guts typically derive their texture from an extra filament (raised ridge) on the surface. Polys typically derive their texture from a dented or rough surface. In each case these string provide better string on ball friction, which enhances spin. Examples include:

Textured Nylon:Gamma Ruff, Prince Topspin w/Duraflex
Textured Poly: Kirschbaum Super Smash Spiky, Luxilon ALU Power Rough.


A combination of different materials blended together in an attempt to bring out the best features of each material. For simplicity, strings combining different grades of nylon, which are theoretically also composite strings, aren't included in our list.

Head FXP Tour
Isospeed Axon Multi
Wilson NXT Control

Monofilament Polyester & Co-Polyester

Polyester and co-polyester monofilament strings are extruded as a single strand. Traditional 100% polyester strings typically have higher stiffness values and are best for advanced players seeking maximum control and lots of off center feedback. Co-polyester monofilaments are made with additives to increase elasticity and comfort, though they are still firmer than most nylon based strings. Many of today's co-polyesters are constructed with low-friction coatings to enhance "snapback" which increases spin. Shaped Polyester strings are made with edges which grip the ball more effectively so that more spin can be applied. Textured or Rough Polyester also offer better grip on the ball for added spin. Poly-based monofilaments are ideal for big hitting intermediate and advanced players who want durability, control and spin.
Babolat RPM Blast (co-poly, shaped)
Gosen Polylon (traditional, great value)
Gosen Sidewinder (shaped, twisted)
Kirschbaum Super Smash (traditional, firm)
Super Smash Spiky (traditional, textured)
Luxilon ALU Power Rough (co-poly, textured)
Polyfibre TCS (co-poly, comfortable)
Solinco Tour Bite (shaped)
Tourna Big Hitter Black 7 (co-poly, shaped, comfortable)
Volkl Cyclone (co-poly, shaped)

Aramid Fiber Hybrids

Combines the strength and abrasion resistance of Kevlar mains with nylon (synthetic gut) crosses. Most durable of all string construction, but least "playable" due to Kevlar's extremely stiff, dead feel. All current Kevlar string sets are hybrids, combining Kevlar mains and synthetic crosses

Ashaway Crossfire
Prince Pro Blend


String tension is the final piece in the racquet-string-tension triad. It's also the least understood by most recreational players. Let's start with the basics - lower tensions provide more power, tighter tensions provide more control. This is a very general rule of thumb and assumes a certain level of player ability (especially the control part). A beginning player may need more control but tighter string tensions aren't the solution. This player needs a soft, forgiving stringbed that lower tensions provide due to the frequency of off-center hits. Advanced players who swing fast and hit hard usually need more control and will, therefore, benefit from tighter tensions. There are, of course, always exceptions but these generalizations apply to the majority of players.

Each racquet has a recommended tension range. This range has been determined by the manufacturer as a result of extensive playtesting by real players. If a player doesn't have a specific need (more power, arm problems, etc.), he should start at mid-range and make any adjustments from there.

Otherwise, here are some specific guidelines for selecting a string tension.


As we stated above, if a player is seeking more power from his racquet, he should try dropping tension a few pounds. The stringbed will deflect more (and the ball less), returning greater energy to the ball. There is a point of diminishing returns where the stringbed turns into a butterfly net, but it's well below any racquet's recommended tension range.


A tighter stringbed deflects less and deforms the ball more, providing less energy than looser strings. This means the ball won't fly as far when you hit it. Beginners who are shanking the ball in every direction won't gain any advantage by increasing tension, but intermediate and advanced players who are hitting a lot of long balls will be able to reduce the depth of their shots without changing their swing. It is also generally accepted that spin potential is enhanced with higher tensions, which provides even more control for topspin and slice players.

Arm Injuries - lower tensions result in a softer stringbed and a larger sweetspot, reducing the amount of shock and vibration transmitted to the hand and elbow.

Switching Racquets - too many players are stuck on a tension ("I always string my racquet at 60 pounds") and don't make allowances when changing racquets. Whether changing head sizes, brands, or buying a new titanium racquet, a player will need to make the corresponding tension change. If 60 pounds was mid-range on his old racquet and the new racquet's tension range is 50-60 pounds he should start at 55 pounds with the new racquet.

Switching Strings - if a player changes from a soft string (natural gut, syn gut, multi) to a poly-based string, we suggest reducing tension 5-10% to compensate for the higher stiffness. This is more art than science and may require trial and error to get the feel exactly right. When switching to Kevlar be advised that this material is much stiffer than nylon synthetics and quite a bit stiffer than most ploy-based strings - so tension accordingly.