Tennis Strings

Solinco Confidential Review

A four sided co-polyester monofilament designed for advanced players craving control. How does it play?

Solinco Confidential officially launched in 2020 after being available privately for around three years to a group of select customers and retailers that were on board with the brand.

The string was initially developed for touring pros, as a string that used Solinco's signature blend of spin, power and control with added playability.

It sits in the middle of Solinco's core string lineup and is slightly softer than Tour Bite but slightly stiffer than Hyper G. It is available in 16, 16L, 17 & 18 gauges in both 12-meter individual sets and 200-meter reels.

For this playtest, I picked up a pack of 16 gauge for $10 (ยฃ8) and took it to the outdoor clay courts for some summer tennis.

Solinco Confidential Specification

solinco confidential spec

String Specs:

  • Co-poly monofilament
  • 4 sided profile
  • Gauges: 1.15 mm, 1.20 mm, 1.25 mm, 1.30 mm
  • Colour: Dark Silver

I am currently using a Wilson Pro Staff 97 V13. This is a precision and control type racket, and before stringing with Solinco Confidential, I'd been using a full bed of Tecnifibre Triax in it. 

It has no customisations other than a Tecnifibre overgrip and, when strung with the Confidential (which weighed around 24g including the cable tie), came in at 338g total weight.

I strang the racket myself using my MiStringer, a cool portable stringing machine that does a decent job. I set the tension to 25 kgs (55 lbs) with Confidential 1.30 mm gauge.

This was the first time in a while I had strung a racket with polyester, and with the slightly thicker gauge, I found it quite tiresome. However, I eventually got the job done and opted to do it as a one-piece string job.

Solinco Confidential Full Review

solinco confidential stringing

There was around a 24-hour gap between the stringing and the first playtest. I played on outdoor clay courts. The hit consisted of a short court warmup in the service boxes and then more regular hitting from the baseline, which gradually increased in intensity, some point play and then a set of doubles to finish things off.

Initial Thoughts and How It Felt

confidential closeup

For the last six months, the string I've been using is a full bed of Tecnifibre Triax, which is a multifilament with co-polyester fibres integrated.

Triax is a fairly soft string designed to offer some characteristics of polyester while being arm friendly, durable and somewhat natural gut like.

Changing to a full bed of a stiffer polyester was a big change, and during the first 45 minutes of play, I found Solinco Confidential to be board like and underpowered. 

However, that is nothing out of the ordinary for polyesters, and I also had the tension up at 55 lbs. However, it wasn't long before the string settled in and became a lot more playable.

How It Played

solinco confidential reviews

The more intense hitting coincided with the string losing its initial board like feel, and my perspective on the string changed pretty quickly. Hitting went from meh to bweh.

From struggling with it early, my shots began to have a tad more power, and I had a much better idea of where the ball was going.

My favourite aspect of Solinco Confidential was how well it suited my backhand slice, and I was able to feel like I had the ball on a string when playing singles points and a set of doubles.

Even on the defensive, hitting more of a higher, loopier trajectory shot, the ball kept landing where I hoped it would, and it offered me a great deal of consistency from that wing. 

It was equally impressive on the more aggressive slice, or when I sliced the return of serve, the string helped me produce a nice skidding ball. 

I also enjoyed hitting the forehand with Solinco Confidential; while it didn't give me much in the way of easy power or help me blaze winners, It offered plenty of ball pocketing, and I could produce good amounts of topspin. I also felt strong when hitting on the run as producing sharp; dipping angles came very easily.

On serve, Confidential offers a lot of control and precision. It doesn't give free power, but I felt like I knew where the ball was going and could find the lines when I wanted. Which in turn lets you swing more confidently, play looser and thus generate more pace.

I do not have a big kick serve, but my second serve had some nice dip on it which I don't typically get with other string setups I've used.

Overall, the standout feature for me was the predictable response from the stringbed. It didn't have a high launch angle that catches you by surprise. Confidential feels like a string you can depend on to deliver shot after shot with what you expect it to.

Durability and Price

I'm not a string breaker and considering this was 16 gauge, the chances of me busting a string here were low.

After around 12 hours of play, I see some light notching, so even for bigger spin hitters who burn through strings for fun, Solinco Confidential is going to last a good amount of time.

In terms of price, it's around $12 for a packet, and I think that makes Solinco Confidential a decent buy. It's not quite at the no brainer price level, but it's more than affordable.

I also believe it outperforms several polyester strings that come in with much higher price tags, so if a comfortable polyester string is what you are looking for, this is a worthwhile buy.

Tension Maintenance


The racket was strung at 25 kg using the MiStringer. I tested the tension around 30 minutes after completion using the TennisTension App, and it came in at 23.2 kg, which is around what I expected.

After two separate hitting sessions of two hours each over two days, I took another reading, and it came in at 19.1 kg. 

Once it settles, Solinco Confidential holds tension very well, and I believe it plays its best after the first 45 minutes of hitting and is going to be at its optimum for around 8-10 hours of play depending on how hard you hit the ball or how often you break strings. 

The first few hits feel a bit board like, but after that, it settles into a very predictable stringbed, and I think even for big hitters, they'll get ample playtime from it before the tension drops off a cliff.

Who Is This String For?

solinco confidential reel

It's best to look at who this string is not for, and based on my testing so far, it's not a string for beginners, nor is it one for those with arm issues.

Fortunately, I've never really had any elbow issues, so I'm not best placed to comment on how arm friendly a string is, but what I can say is that while it's not the stiffest string on the market and errs more towards a โ€˜comfortable' polyester, it still has that rigid feel to it so you can't call it โ€˜arm friendly'.

Instead, it's a string for players who want to rip the ball and get a consistent, predictable response shot after shot.

Solinco Confidential is also ideal for those who want a durable string and offers some of the best tension maintenance I've come across when using polyester strings.

Find Your Ideal Tennis String

tennis string finder

Are you looking for a new string to try in your racket? Use our easy to use tennis string finder tool. It lets you filter by string type, gauge, colour, price, stiffness and shape.

Final Thoughts

Solinco Confidential is one of the best polyester strings I've played with.

It holds tension exceptionally well and offers a consistent playing stringbed that gives you predictability every time you make contact with the ball, be it on the forehand, backhand, slice or serve.


  • Very predictable response
  • Excellent tension maintenance
  • Above-average durability


  • It may be too soft for players who generate significant RPM's

Have you tried Solinco Confidential? Have any questions about it? Let me know in the comments below.

Solinco Confidential Review

Power - 7.5
Control - 8.5
Comfort - 8
Touch / Feedback - 8
Spin - 8
Snapback - 8
Durability and Tension Maintenance - 9



A cost-effective and highly predictable response are Solinco Confidential's standout features.

User Rating: 3.68 ( 16 votes)


Huge fan of Roger Federer. I watch all his matches from Grand Slam level right down to ATP 250. When I'm not watching or writing about tennis I play regularly myself and have a keen interest in tactics, equipment and technicalties of the sport.

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  1. Somehow it doesn’t hurt so much that Djoker comes from Tokyo with empty bag? ๐Ÿ˜‰ Beating by Zverev was somehow within reality, but to PCB?
    Maybe he took serious what some former greats are telling: the best is if all Big3 stay with 20-20-20 for ever ๐Ÿ™‚

      1. I know, Alison. But it’s called “Golden Slam” (4 GS + Olympics). And after the Tokyo effort (and they say some shoulder injury) the chance for USO crown seems to have dropped.
        While I don’t care about goat debate, the final outcome for Big3 like 20-20-20 would be perfect. From the Big3 only Djoker seemed to have still potential to win more. But it seems, the pressure from younger players is still rising and maybe neither Rafa nor Novak would have easy ways to win more slams.

      2. “And after the Tokyo effort (and they say some shoulder injury) the chance for USO crown seems to have dropped.”
        I’ll believe that when I see it. If an abdominal tear doesn’t stop him …

  2. Very pleased indeed for Sasha .Deserves this.
    I think in one or two years(please God) we may see a definite changing of the guard.
    Sasha ,Thiem Tsispas.,Shapavalov.They are the future of tennis.
    Enough of the old guys.

      1. Yes. But I think, Djoker has had something. My speculative theory would be, he’s got Covid again (it’s possible after more than 1 year from the first infection) and had some symptoms. I don’t see any reason for him to have a shoulder injury. It was diplomacy. And then he withdraws from Cincinnati (from Toronto before Tokyo.

      2. Could have had false negative. Bad had obviously symptoms of some infection and it was not the shoulder.
        About how good tests are, ask Jonathan ๐Ÿ˜‰
        And why shouldn’t he play with Covid, if the whole staff of OL was vaccinated?
        And given there is no evidence (ask Jonathan again for evidence) of existence of the virus, of the virus to be contagious, of the virus to come from animals or Chinese+American experts working together in Wuhan (last news from US Republicans, saying, they have EVIDENCE).
        Instead of worrying about Covid, watch this ๐Ÿ™‚

      3. I didn’t watch any of the tennis, zero interest in Olympic tennis for me. I heard shoulder injury for Djoker.

        Athletes are tested daily.

    1. So, you mean, first enough of The Federer?
      The future of tennis is 195-198 cm (and 2,0 m+ serving monsters) and this is a kind of tennis, I will never follow. So only Sasha from the 4 you named, maybe Tsitsipas.
      Thiem and Shapo are like Gasquet. Excellent skills, nice to watch, but … the newest generation ate all high boys (Sinner, Korda, Medvedev …). Thiem and Shapo must very soon take a lot of lessons from Federer or they will never reach slam finals.
      I’,m Thiem’s close follower. I’m not sure if he comes back to his best any time soon (or at all). When his wrist is OK and he reaches his high level in training, he will probably try. IMO he should go back to clay and to old full-swing technique and he may have a chance to win Paris and some clay tournaments, maybe Australian Open or USO, but not with the technique he adapted to have 2019-2020 big time on hard courts. He is not designed for this kind of tennis. He will get injuries and probably call it a career before next serious injury happens (like Fed should have done BEFORE the knee story). When Fed and Thiem are done, I may stop to watch tennis.

  3. Any news, Jonathan, about Fed preparing for US Open/Rod Laver Cup?
    Thiem just started to hit with the right hand, but so far only soft balls. Still some progress from hitting lefty ๐Ÿ˜‰

      1. Thanks ๐Ÿ™‚ So, kind of preparing for US. At least Croatia didn’t have so far big heat and wildfires ๐Ÿ™‚

      2. Surprised Jon hasn’t started a “Fed withdraws from Toronto/Cincy” thread yet. Does this mean it’s not real? ๐Ÿ™

  4. Update – this string died for me around the 15-hour mark I think. Lost its playability, still has some tension but lost that snapback and I have a lot less control.

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