What is the effect of sponge hardness/density?

What is the effect of sponge hardness/density?                                                                                                                        

Sponge Thickness Plays an Important Role in Performance

 Answer by: Samson Dubina, Rated 2461, 2009 US Men’s National Finalist

The hardness/density effects how deep the ball sinks into the sponge.  Softer sponge will have more dwell time and allow the ball to sink deep giving the ball a higher arch.  Most loopers and those focusing on spinny shots and more arch prefer soft sponge.  Softer sponge is lighter in weight and makes it easier to perform more spin on the slow shots: loop against backspin, chop, and push.  Harder sponge has less dwell time and does not allow the ball to sink deep into the sponge.  Many aggressive counter looping players prefer harder sponge because there is more potential for power and spin from mid-distance.  Although harder sponge is heavier, one must also consider the sponge thickness when gauging the weight.

 Most rubbers have two versions, a soft one and a hard one; for example Narucross EX Hard and Narucross EX Soft.  This doesn’t mean that the hard is extremely hard or the soft is extremely soft.  It just means that one is softer than the other.  Before purchasing a rubber, consult the Paddle Palace Catalogue review on each rubber.

* Softer sponge has more dwell time

* Softer sponge has more spin on the slow shots

* Softer sponge has the same or slightly less spin on the power shots

* Softer sponge is lighter


 Answer by: Massimo Constantini, ICC Head Coach, ITTF High Performance Coach

 The use of a hard, dense sponge follows the same rules as sponge thickness. If you play with a hard, dense sponge you won’t have a good quality of spin and control but you’ll have a good quality of speed. The ball bounces on the rubber and quickly leaves the surface to travel away. If you use a soft sponge you may have a better control because the ball, when bouncing on the rubber, stays for awhile longer and gives a fraction of second to the player to manage it. 


Answer by: Sara Fu, Texas Wesleyan University Team, 2011 NCTTA Women’s Singles Champion and Mixed Doubles Champion, Rated 2437.

It depends on what kind of blade you use. If you play with a faster blade, then you would like to choose softer sponges. If you use slower blades, then you would like to choose harder sponges.


Answer by: Tahl Liebovitz, USATT National Coach and Paralympic Gold Medalist

The harder the sponge, the more spin you will be able to generate.  If you have very sound strokes you should probably use harder sponge.  The two best sponges I played with from STIGA were the Boost TC and the Boost TX

For me the Boost TX is the best rubber I have ever used.  The sponge is medium hard and I am able to produce great spin when I serve and also when I attack. 

I would try to use a medium hard sponge if you can.  Most players like to use softer sponge.  However in my experience using a harder sponge produces a better quality ball.  I would always recommend trying to use the hardest sponge you are comfortable with. 

Most players are not comfortable using Chinese sponge.  It is best to use a rubber with Japanese sponge.  Try and find a medium hard rubber.  For me Boost TX is the best rubber I have used.  I use 2.3 mm sponge thickness.


Answer by: Stellan Bengtsson, Only player to have won singles, doubles and teams at both the Worlds and Europe Championships. 67 International singles, doubles and team titles. Coached Jorgen Persson, JO Waldner, Peter Karlsson and Erik Lindh, all World and Europe Champions.

A hard dense sponge gives less control and a faster ball. The ball has less time on the racquet, i.e. shorter blade to ball contact. The overall affect also depends on
the friction of the rubber.


Answer by: Scott Lurty, Rating 2328, SPIN New York Coach

Softer sponge allows for more dwell time on the racket, and hence make shots such as looping easier. However they are also more reactive to incoming spin than harder sponge. Harder sponge is less forgiving but actually has better directional control.


  1. Interesting the variability of the comments. Sara Fu makes a key point-the type of sponge is very much influenced by your blade. Samson also notes that the speed and type of shot is important in this discussion. Some comments appear to be made assuming one is using a carbon or other fast/stiff blade. Combining all answers I think gives the best response to the question.

  2. The thickness, density, or hardness of the sponge has no direct relationship to the speed after impact. It is the ability of the sponge to return to its original shape as quick as possible after being deformed that affect the speed of the ball after impact. If the sponge can return to its original shape quickly and stay in contact with the ball longer it will return more energy and therefore speed to the ball. A sponge that deforms and doesn’t spring back quickly to stay in contact with the ball will not be fast no matter how thick or dense it is.

    Think of where the energy goes when the ball has stopped relative to the blade. The blade has flexed some, the rubber has been compressed and the ball is deformed. Now think about how each of these three things return energy to the ball. Not all the energy is returned to the ball. There is internal resistance or damping that makes the impact less than 100% efficient. A thicker rubber isn’t necessarily more efficient nor is a harder rubber.

    I agree with those that said that softer sponge will generally create more spin because the ball will sink into the rubber more but again it is really an efficiency problem. If a soft rubber simply cups the ball so the ball doesn’t slip relative to the top sheet, the spin is limited to the tangential speed of the paddle. Rubbers like T05 will stretch the rubber a bit across the surface and spring back providing extra spin so even though T05 is harder than many defensive rubbers it still will generate more spin with the same tangential paddle speed.

    Of course things change when the rubber ‘bottoms’ out. Then it is the ball and blade that do the rest of the deforming.

  3. Generally speaking for an offensive player, in my opinion, use softer rubber on the powerful 4H and harder rubber on the BH because you want more speed with a less powerful stroke and dwell time on the rubber.

    • Paddle Palace

      Hi Tom,
      Thanks for your comment. Please tell me your rating, as well as the blade and rubber your use.
      Paddle Palace

      • I use Juic Varites 2.0 on my BH and Juic 999 2.0 attack on my 4H, Hunter Pyro Blade. I loop and hit on both sides. I punch block too on the BH.

        I am considering switching to 1.5 sponge on both sides since I am not convinced, the ball even at the highest speeds, ever penetrates the rubber to the fullest extent.

        • Has a scientific study ever been done at what speed the ball
          fully penetrates the rubber to the blade, including both top sheet and sponge ?

          It also depends on the structure of the top sheet inward pips and how they react with the sponge.

        • Hi Tom,
          Thanks for your emails.
          It would be very helpful to know your rating before answering your question. So please send that along.
          I will be following up on your question about a scientific study related to ball speed…stay tuned.

  4. As there are two kinds of hard and soft rubbers, Chinese tacky and grippy European/Japanese, there are several ways of classifying things. First off, the Chinese tacky rubbers favor the forehand. There are some people who like using them on the backhand and I cannot understand why, but its their preferance so I won’t judge them. Usually harder sponge favors forehand strokes utilizing more body power, as you will get the better speed when using more power. Hard tacky rubbers are the choice forehand rubber for the Chinese national team, as well as most Chinese loopers. Whereas the European and Japanese players use the softer sponged TENERGY and such rubbers in their forehand because they usually have counter and blocking styles, like Timo Boll and Kenta Matsudaira. (Generally if you can generate your own power you want a faster blade with slower rubbers, and if you rely on other players’ power the faster rubber with a slower blade would be appropriate). Then there are he exceptions, the soft tacky rubbers and hard grippy rubbers. One soft tacky rubber I have found is the Double Happiness G555. The G555 is very soft and tacky and is excellent at producing masses of spin, but cannot produce the speed of say, Aurus. I have not used any hard sponged grippy rubbers, but one I take to be hard sponged and european is the Boost TX as Tahl pointed out. Usually these rubbers (soft and tacky and hard and grippy) aren’t adopted into the modern game because they need different techniques to bring out the best in them. One reviewer of the Boost TX complained that the sponge was too hard, thus needed a more Chinese style forward loop tp get the best out of, and therefore didn’t like it much. Reviewers of the G555 complained that it was too slow.
    Then there are the hybrids, combining both European/Japanese and Chinese qualities. One example is the Butterfly Spinart. Spinart has been reviewed as having an extremely hard sponge, being extremely heavy, and semi sticky. It has been said that people generally don’t like it much but I think that some of those reviewers aren’t using it right, or they don’t have the right skill to use it well.
    As some forumers say, you just need Sriver to get to USATT2000 but I saw a 1400 with Acuda S1 Turbo max both sides on an Epox Topspeed. All he could do was smash. When I looped against backspin, he told me he didn’t know how to loop.

    As for the bottoming out, when the ball contacts the blade surface you don’t have the usual springiness of the sponge to cushion the ball and then throw it back out as the sponge is completely crushed and needs more time to reform. Thus the blade acts as more of a sponge than the sponge itself, although to a lesser degree. If you have a more flexible blade you can produce more spin but less speed on a bottoming out shot. If you have a stiffer blade you can produce more speed than spin on a bottoming out shot. But keep in mind that bottoming out makes the rubber produce way less spin and speed than a regular looping shot.

    To try bottoming out at home, try flat hitting. The sound is usually an indicator of how deep you have penetrated.

    But I’m only a standard 1000ish player so you can ignore me.

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