String Playtest: Mantis Comfort Synthetic

The Mantis Comfort Synthetic 16-gauge is available in natural ivory or black, and in a 656-foot reel.

Mantis is a relative newcomer to the string business, but the team behind it has a wealth of experience within the tennis industry.

With headquarters in the UK, Mantis has just entered the U.S. market with four strings, one of which is Mantis Comfort Synthetic, a multifilament constructed of thousands of micro fibers, with a nano coating to provide superb feel. It is covered with highly durable monofilaments before the string is coated using a special elastic resin bonding process.

Mantis tells us that Comfort Synthetic is specially developed to provide a soft string with gut-like feel and playability with the special double coating to enhance durability. Mantis developed Comfort Synthetic for players looking for a gut-like multifilament at a great price, as well as for players looking for a soft string to use in a poly hybrid.

Comfort Synthetic is available in 16 and 17 gauges in natural, fluorescent yellow, and black. It is priced from $5 for sets of 39.4 feet (MAP $9), and $50 for reels of 200 meters (MAP $90). For more information or to order, contact Mantis at 630-325-6600, visit Mantis Tennis Strings, or e-mail

In the Lab

We tested the 16 gauge Comfort Synthetic. The coil measured 40 feet. The diameter measured 1.31-1.33 mm before stringing, and 1.25-1.26 mm after stringing. We recorded a stringbed stiffness of 75 RDC units immediately after stringing at 60 pounds in a Wilson Pro Staff 6.1 95 (16 x 18 pattern) on a constant-pull machine.

After 24 hours (no playing), stringbed stiffness measured 68 RDC units, representing a 9 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. In lab testing, Prince Synthetic Gut Original has a stiffness of 217 and a tension loss of 11.67 pounds, while Mantis Comfort Synthetic 16 has a stiffness of 175 and a tension loss of 14.4 pounds. Comfort Synthetic added 13 grams to the weight of our unstrung frame.

The string was tested for five weeks by 37 USRSA playtesters, with NTRP ratings from 3.5 to 6.0. These are blind tests, with playtesters receiving unmarked strings in unmarked packages. We did advise playtesters to keep the reference tension between 58 and 63 pounds, as recommended by Mantis. Average number of hours playtested was 28.7.

Comfort Synthetic feels soft and thinner than its gauge when you first take it out of the package, with no coil memory. Because of the softness, we had some difficulty with blocked holes.

No playtester broke his sample during stringing, one reported problems with coil memory, none reported problems tying knots, and one reported friction burn.

On the Court

Our playtest team loved the comfort afforded by Mantis Comfort Synthetic, rating it the third best string in this category of the 146 strings we've playtested to date for publication.

Given that the first-place string in this category is a natural gut, this means that Mantis Comfort Synthetic is the second best synthetic string for Comfort in our playtests. Our playtesters also liked the Touch/Feel of Comfort Synthetic, rating it ninth best of the strings we've playtested to date. In addition, our playtesters rated Mantis Comfort Synthetic well above average in the Control, Playability, Power, and Spin Potential categories. As a result, Mantis Comfort Synthetic's overall score is well above average.

Five of our playtesters broke the sample during the playtest period, one each at seven, eight, 12, 17, and 30 hours.


Mantis Comfort Synthetic's high scores are exciting, not only because it's always nice when a string tests well, but also because Mantis currently has three other strings — Power Synthetic, Comfort Polyester, and Power Polyester — that, if each lives up to its name, will give players some clear string choices. It certainly doesn't hurt that Mantis Comfort Synthetic has come in as our third most comfortable string to date, given its moderate price and great margins.

Playtester Comments

"From the very first hit, this string has the 'wow factor'! The combination of comfort, playability, and control is outstanding. I keep waiting for it to lose resilience and control." 4.5 male all-court player using Prince O3 Hybrid Hornet MP strung at 55 pounds LO (Prince Synthetic Gut Multifilament 17)

"This string feels good right out of the box. The power is on the low side. My arm loves it!" 4.5 male all-court player using Head CrossBow 4 strung at 58 pounds CP (Head Sonic Pro 17)

"This string is soft without being mushy. The response is pleasingly crisp and the sweet spot is generous. I would definitely carry this in our shop." 4.5 male baseliner with moderate spin using Head Youtek Prestige MP strung at 60 pounds CP (Head Sonic Pro 17)

"Excellent power, spin, and control. Higher tensions do not cause discomfort. The tennis elbow crowd will love it. It should appeal to a wide range of players." 3.5 male all-court player using Volkl Tour 10 MP strung at 61 pounds CP (Gamma TNT2 17)

"Super soft, with heavy spin and big dwell time. Decent power from the baseline, great touch at net. Tons of pop and spin on serves." 5.5 male all-court player using Wilson K Blade Tour strung at 58 pounds CP (Wilson NXT Tour 17)

Playtester Ratings

(compared to other strings)
Number of testers who said it was:
much easier 9
somewhat easier 14
about as easy 14
not quite as easy 0
not nearly as easy 0
(compared to string played most often)
Number of testers who said it was:
much better 2
somewhat better 11
about as playable 9
not quite as playable 13
not nearly as playable 2
(compared to other strings of similar gauge)
Number of testers who said it was:
much better 0
somewhat better 10
about as durable 18
not quite as durable 7
not nearly as durable 2
From 1 to 5 (best)
Playability 3.6
Durability 3.4
Power 3.5
Control 3.7
Comfort (3rd best) 4.0
Touch/Feel (9th best) 3.7
Spin Potential 3.4
Holding Tension 3.2
Resistance to Movement 2.9

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