Tennis Industry magazine


Playtest: Wilson Natural 16

By Greg Raven

Wilson Natural is a 100 percent natural gut string. According to Wilson, it contains the highest quality natural gut fiber with moisture-resistant long-life coating. Wilson tells us that it is the choice of top players such as Roger Federer, Lindsay Davenport, Venus Williams, Nicolas Kiefer, and Serena Williams.

Wilson Natural

Wilson says that Natural is for any player — from beginner to top-level — who is looking for the best performing string on the market.

Natural is available in 15L (1.35mm), 16 (1.30 mm), and 17 (1.25 mm) in natural only. It is priced from $37 per set of 40 feet. For more information or to order, contact Wilson at 773-714-6400, or visit

In the lab

We tested the 16-gauge Natural. The coil measured 39 feet 10.5 inches. The diameter measured 1.30-1.32 mm prior to stringing, and 1.22-1.23 mm after stringing. We recorded a stringbed stiffness of 81 RDC units immediately after stringing at 60 pounds in a Wilson Pro Staff 6.1 95 (16×18 pattern) on a constant-pull machine.

After 24 hours (no playing), stringbed stiffness measured 76 RDC units, representing a 6 percent tension loss. Our control string, Prince Synthetic Gut Original Gold 16, measured 78 RDC units immediately after stringing and 71 RDC units after 24 hours, representing a 9 percent tension loss. Natural added 17 grams to the weight of our unstrung frame.

The string was tested for five weeks by 38 USRSA playtesters, with NTRP ratings from 3.5 to 6.0. These are blind tests, with playtesters receiving unmarked strings in unmarked packages. Average number of hours playtested was 28.9. Playtesters were given the option of pre-stretching the string, but pre-stretching is not necessary.

As it comes out of the package, Natural is clear enough that you can see through it, and you can see the twisted strands of serosa. Natural has a nice scent, probably from the coating. Natural is not as smooth as some other natural guts, but the “roughness” seems to come from the edges of the strands of serosa, not from flaws in the string. Some of the coating flakes off during stringing, but the flakes brush right off of the stringing machine. The coating seems to double as a lubricant for easier stringing, but did not get on our hands. We chose not to pre-stretch Natural, and there was very little coil memory or kinking. We also tried installing Natural in a racquet with a fairly tight 18 x 20 stringbed, using a “box pattern” that made the last six crosses very difficult to pull through. Natural did not unravel, which can happen with natural gut under these conditions.

No playtester broke the sample during stringing, 11 reported problems with coil memory, two reported problems tying knots, and one reported friction burn.

On the court

Our playtest team gave the highest rating we’ve seen in 102 string tests to Wilson Natural. And some of the ratings weren’t just a little higher than the second-place string; they were a lot higher.

Wilson Natural garnered first-place ratings in Playability, Touch/Feel, Comfort, and Spin Potential by huge margins over the next-highest-rated strings. Natural also claimed first-place ratings in Power and in Control, along with a sixth-place rating for Holding Tension, a rating well above average for Resistance to Movement, and even an above-average rating for Durability. As a result, Wilson Natural’s overall average rating blew the roof off our previous high rating.

Wilson Natural also set a record for highest rating for playability for a test string compared to the strings preferred by our playtesters, and it did so by a wide margin.

Also, while the average longevity of strings used by the members of our playtest team was 28.56 hours, this same team on average tested Wilson Natural for 28.93 hours.

Eleven playtesters broke Natural during the playtest period, one at 3 hours, two at 5 hours, and one each at 5.5, 7, 8.5, 14, 25, 28, and 35 hours.


It’s no surprise that Wilson Natural tested highly: No matter what advances there are in new string materials, natural gut still has the reputation of being the best. But it is a surprise that it tested as highly as it did. If our playtest team is any indication, natural gut’s reputation is well deserved. Wilson Natural tested so well with our playtest team that it’s difficult to imagine another string generating better ratings.

Two other surprises in this string playtest are Wilson Natural’s durability and ease of stringing. Not only did our playtesters award Wilson Natural an above-average rating in Durability, they themselves used the string on average for longer than they use their normal strings. Because natural gut is perceived as difficult for the novice to string, we published a first-time stringing guide for natural gut in the March 2006 RSI. While only six of our 37 testers said installing Wilson Natural was easier than other strings, more importantly, 20 told us it was about the same, and not one of our playtesters broke his sample during installation.

For years, stringing experts have told players looking to mitigate or eliminate arm sensitivity (AKA tennis elbow) to switch to natural gut. Again, the ratings of our playtest team (and the accompanying comments) bear out the wisdom of this recommendation. And judging by the ratings in categories other than Comfort, many of the traditional “down sides” of using natural gut are no longer applicable.

Playtester Comments

“Great string! Good feel.” 5.0 male all court player using Prince 03 White strung at 62 pounds CP (Gamma Power Play 18)

“String plays great and holds tension well. Never felt dead, even just prior to breaking. I would consider using this over my current gut set-up!” 5.0 male all court player using Wilson nSix-One 95 strung at 55 pounds CP (Babolat gut 16)

“Plays like an average natural gut—nothing special, though it’s hard to say anything bad about natural gut. Great string!” 5.0 male using Prince Graphite Classic strung at 58 pounds CP (Prince Premier 16)

“Five pounds tighter to resist movement. Great feeling string, very spin-friendly, with great audible feedback. String showed no signs of imperfections. I cannot wait to find out what it is, especially if it’s price is competitive. I have strung more gut in the past 8 months than in the previous 8 years. This string would definitely fit into our line-up.” 5.0 male all court player using Head Liquidmetal 1 strung at 58 pounds CP (Babolat VS Feel/Luxilon Big Banger XP 16)

“Didn’t unravel during stringing, but required extra care. Played great! It should really—natural gut. Wish I could talk more people into playing natural gut. There is no substitute. This stuff is excellent. Easily the highest rating I have given.” 4.0 male all court player using Prince Precision Mono 650 strung at 60 pounds LO (Gamma TNT2 16)

“Looks like gut, smells like gut, plays like gut. Seems to fray quicker than I remember. I will be curious about price as it has the same qualities as the premium gut I normally use.” 5.0 male baseliner with heavy spin using Head FXP Instinct Team strung at 60 pounds LO (Wilson Sensation 16)

“Excellent string, however, became frayed after 20 hours. Great feel, touch, and power.” 4.5 male all court player using Wilson n5 strung at pounds LO (Head Fibergel Power 17)

“Very lively string with super spin. I had to reduce my power level to get the best control/playability. (PS: I did pre-stretch.)” 4.0 male all court player using Head Liquidmetal 1 strung at 62 pounds (Babolat Attraction 16)

“This gut feels great. Awesome feel and durability. Fraying occurs, but only after 20 hours. I’ll definitely recommend this to gut lovers. I will carry this in my shop!” 5.0 male baseliner with heavy spin using Babolat Pure Control + strung at 62 pounds CP (Babolat Super Fine Play 17)

“I really felt comfortable playing with this string.” 5.0 male all court player using Prince 03 White strung at 60 pounds CP (Prince Premier 16)

“Feels like gut—both in stringing and playing. I would use it to play and teach with.” 3.5 male serve-and-volleyer using Wilson nForce strung at 60 pounds CP (natural gut 16)

“I actually enjoy this string. Good feel with power and control. Lends to good stroke production and reliability.” 4.5 male all court player using Head Flexpoint 4 strung at 61 pounds CP (Gamma Pro 17)

“Coating made for easy stringing and prevented early fraying. Heavy spin did not cause early string movement. Very comfortable in all playing areas—very soft. Excellent feel on ground strokes, serves, and volleys. The string’s coating works very well. After 16 hours of playing with D1 collegiate players, the string held-up very well. There was no fraying and very little string movement. I am partial to gut, however the price prevents daily use. I would definitely use this string in competition.” 5.0 male using Babolat Pure Control Zylon strung at 54/62 pounds (Various 17)

“What’s not to like about playing with natural gut? Great pop, excellent control, touch, and feel. There is not a more arm friendly string made. After about 10 hours the string began to fray. After 20 hours it still felt freshly strung. After 25 hours there was considerable fraying, though they still feels lively.” 4.0 male serve-and-volleyer using Völkl Catapult 7 strung at 60 pounds CP (natural gut 16)

“This is the best string that I’ve tested in three years. I was most impressed by the power, playability, control, touch, and feel. I feel like the overall performance of this natural gut string greatly exceeds the top multifilaments. I plan to add this string to my list of favorites.” 5.0 male baseliner with moderate spin using Wilson Hyper Pro Staff 6.1 strung at 60 pounds LO (Wilson Sensation 16)

“This string had a great feel from the start and with the usual natural gut control. I found it not as apt to fray as other natural gut strings. Tensioned remained solid with good response throughout. A very likeable string. with lasting durability. Great for those with a need for feel and more durability.” 5.0 male serve-and-volleyer using Wilson nSix-One 95 strung at 60 pounds LO (Wilson NXT Tour 17)

“Stringing was typical of natural gut as care was needed and extra time required; however, there were no surprises. As with all natural gut, I pre-stretched. With an entire four weeks of playing and teaching, this string showed little fraying (which is amazing for a natural gut). Surprise never stopped, as this particular string showed very little movement. This string is by far the most durable natural gut I have ever used. Playability was very good, however, it actually played better at higher pace. It played relatively firmly from the baseline, yet was still soft and playable at net. Would definitely try this string once again at lower tension to enhance the feel from the baseline and would definitely carry in my pro shop due to excellent durability.” 4.5 male baseliner with heavy spin using Head Flexpoint Radical MP strung at 62 pounds CP (Gosen Polylon SP 17)

“This is a very good string that I would use anytime.” 3.5 male all court player using Babolat Pure Drive Roddick strung at 63 pounds CP (Babolat Excel or Attraction 17)

“This is an excellent string. I am struck by the instant playability, comfort, and feel. It has very good, controllable power. Spin is adequate for my game. More important is the predictable power for placement. Depending on price, it would be a good string for everyday play.” 4.0 male using Babolat Pure Drive strung at 53 pounds CP (Babolat gut 16)

“The string feels incredible, but broke too soon. Thus, I cannot consider it for personal use or inventory. This might be a good as blend with a poly. I have none of the post-match arm tingles and my shots were definitely more accurate … just wish it were more durable.” 4.0 male all court player using Yonex RDX 500 strung at 63 pounds LO (Wilson Sensation 16)

“I enjoy this string. However, the kinking during stringing seems to compromise durability.” 3.5 male using Head Flexpoint Radical OS strung at 61 pounds LO (Forten Aramid Gear 15/16)

“Not a bad string. I’m not a natural gut user. I like a stiffer feeling string, though this is nice.” 6.0 male serve-and-volleyer using Prince Hybrid Hornet MP strung at 65 pounds CP (Prince Sweet Perfection 16)

“I use gut a fair amount. This string was very easy to install. Not much tendancy to kink, twist, or unwind. Nice and soft to play with, though spongy after a few hours. I think pre-stretching would benefit players who seek better tension holding. I did not pre-stretch.” 5.0 male all court player using Prince 03 Tour OS strung at 68 pounds LO (Babolat VS Touch/ Luxilon Big Banger 15/16)

“It is nice to use gut. Gut has better playability than all other strings, but is too expensive for me.” 5.5 male all court player using Wilson nSurge strung at 60 pounds CP (Wilson NXT 17)

“Much easier than other gut to string. ” 4.0 male all court player using Wilson SledgeHammer 3.8 strung at 64 pounds CP (Gamma Live Wire 17)

“The string was installed without pre-stretching. There were no problems—as easy as any synthetic. The string performs better in the playability characteristics than most other strings I’ve tested. I would have liked better control, but this is still a string I’d purchase.” 5.0 male all court player using Head i.radical OS strung at 63 pounds LO (Gamma Synthetic Gut 16)

“Enjoyed playing with it, but not stringing it. Played very solid, but unusually stiff. Spin potential, control, and touch were noteworthy, but the lack of comfort is a deal-breaker.” 5.0 male all court player using Wilson nSix-One Tour 90 strung at 63 pounds LO (Wilson Sensation 16)

“Great feel, shock absorption, and easy on the arm, but not any more durable than typical gut.” 4.5 male all court player using Wilson H Tour strung at 60 pounds LO (Wilson NXT 15L)

“Great comfort and feel. First day, not much feedback on mishits. Over time, however, more vibration was evident and strings played slightly dead after 15 hours. Two-piece measurement has to be exact—not much excess string.” 5.0 female baseliner with heavy spin using Prince Air DB strung at 59 pounds CP (Gamma Professional 16)

“Although playing at a low tension, the string bed felt stiff and the lack of “pop” noticeable.” 4.0 male all court player using Head Flexpoint 6 MP strung at 52 pounds CP (Gamma ESP 17)

“I really tried to like this string, but I couldn’t. Perhaps I didn’t pre-stretch enough. It simply doesn’t play like I would expect natural gut to play. I cut it out after 15 hours just to replace it with something lively.” 5.0 female baseliner with heavy spin using Head Flexpoint 4 strung at 59 pounds LO (Head Perfect Power/Wilson Reaction 16)

“No liveliness.” 4.5 female all court player using Prince strung at 60/61 pounds LO (Alpha Synthetic Gut 17)

“Additional gain in power is about equal to the loss of control and comfort.” 4.0 male baseliner with heavy spin using Prince NXG Graphite strung at 63 pounds LO (Prince Synthetic Gut 16)

“I don’t like anything about the string. Plays like a board with no touch/feel. Lacks power, touch, and control. This string offers nothing to the already saturated market.” 4.0 male all court player using Fischer Twin Tech 950 strung at 65 pounds LO (Klip X-Plosive Hybrid 16)

(Strings normally used by testers are indicated in parentheses.)


(compared to other strings)
Number of testers who said it was:
much easier 2
somewhat easier 4
about as easy 20
not quite as easy 10
not nearly as easy 1
(compared to string played most often)
Number of testers who said it was:
much better 4
somewhat better 17
about as playable 13
not quite as playable 2
not nearly as playable 2
(compared to other strings of similar gauge)
Number of testers who said it was:
much better 1
somewhat better 4
about as durable 21
not quite as durable 10
not nearly as durable 1
From 1 to 5 (best)
Playability 4.3
Durability 3.3
Power 4.0
Control 4.1
Comfort 4.3
Touch/Feel 4.3
Spin Potential 4.0
Holding Tension 3.8
Resistance to Movement 3.4

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About the Author

Greg Raven  is an associate editor for Tennis Industry magazine and technical writer. He is certified as a Master Racquet Technician by the U.S. Racquet Stringers Association. He can be reached via e-mail at, or through Facebook, LinkedIn, and Twitter. He plays tennis three to five days a week, and is turning into an avid cyclist.



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