[Table Tennis] Rubber Hardness Part 2: Why Modern Rubbers Feel Different

In Part 1, we explored why rubber hardness numbers often fail to reflect actual playing feel.

In this article, we focus on:

modern thin-sheet rubber design
the 4.0mm regulation
why modern rubbers feel softer
how to choose the right hardness

Contents（目次）

４．Behind the Scenes of the “Thin Top Sheet × Thick Sponge” Trend
[Column] The “Magic Racket” and the Birth of Modern Regulations
５．Finding the “Ideal Hardness” for You
６．Summary
- Related posts:

４．Behind the Scenes of the “Thin Top Sheet × Thick Sponge” Trend

The Shift Toward Thinner Top Sheets

Today, the “thin top sheet” trend has become an essential factor when discussing rubber hardness.
In the past, many manufacturers used relatively similar top sheet thicknesses.
However, modern high-end rubbers have shifted toward thinner top sheets and thicker sponges.
This trend has been strongly influenced by the demands of elite players.
Manufacturers now design top sheets as thin as possible in order to maximize sponge thickness within the allowed limits.

（1）The “4.0mm” Regulatory Barrier

Under official table tennis rules, the combined thickness of the top sheet, sponge, and adhesive layer cannot exceed 4.0mm.
Because of this strict limitation, manufacturers try to make the top sheet as thin as possible.
This allows them to maximize sponge thickness within the allowed space.
A thicker sponge improves energy transfer and makes it easier to generate speed and power, even with modern plastic balls.
As a result, many modern high-end rubbers are designed around the concept of a thin top sheet and a thick sponge.

（2）The Risk of “Disqualification”

A natural question arises:
“Why don’t manufacturers design rubbers right up to the 4.0mm limit?”
If a rubber were manufactured at exactly 4.0mm, the additional thickness of glue could easily push it beyond the legal limit.
This would increase the risk of equipment violations at official tournaments.
To avoid this problem, manufacturers intentionally leave a small safety margin in their designs.
They must carefully balance maximum performance with compliance under official regulations.
Modern thin-sheet rubbers are the result of this balance between aggressive engineering and rule compliance.

（3）Representative Product Examples

This modern “thin top sheet × thick sponge” design is mainly found in premium high-end rubbers.
These products combine advanced engineering, high performance, and increased manufacturing costs.
As a result, many of them are positioned in a premium price range.

Butterfly: Xiah 03
- A flagship rubber that combines Butterfly’s latest technologies.
- Designed to transfer the energy of the thick sponge more directly through a thinner top sheet.
STIGA: DNA Platinum
- Uses an extremely thin top sheet to maximize sponge thickness up to MAX (2.3mm).
- Achieves strong ball bite together with powerful rebound.
andro: Rasanter Series
- One of the pioneers of the modern thin-sheet trend.
- Known for its “ULTRAMAX” concept, featuring thinner top sheets and thicker sponges.

（4）Why Thin-Sheet Rubbers Often Feel Softer

The most important change is the shift in “perceived hardness.”
Even when the sponge hardness number is identical, rubbers with thinner top sheets often feel softer during play.
This is because the ball can sink into the sponge more quickly and deeply during contact.
As a result, these rubbers usually provide a stronger sense of “bite” and ball hold.

“Even though the hardness number looked perfect, the actual feel was completely different…”

The true reason for this mismatch may come from the balance between top sheet thickness and sponge thickness.
Modern rubber feel is heavily influenced by the structure itself, not just the hardness number printed in the catalog.
Understanding this structural difference is an important step toward choosing equipment more logically and confidently.

（5）Reference: Butterfly’s Latest Rubber “Xiah 03”

Compared with the earlier Rasanter series, Butterfly entered the “thin top sheet × thick sponge” trend relatively late.
However, Butterfly is globally known for its extremely detailed product development and strict quality control.
It is reasonable to assume that Butterfly delayed this release until they were fully satisfied with the final performance and consistency.
Xiah 03 combines Butterfly’s latest technologies into a premium flagship rubber.
Because of its advanced design and manufacturing costs, it is positioned in a very high price range.
For many players, the price may feel surprisingly expensive for a single rubber sheet.
Still, the unique feel created by this modern thin-sheet structure makes the rubber especially interesting from a technical perspective.

If you are interested, please check the latest price using the link below.

Butterfly Zyre 03

Butterfly Zyre 03 is composed of ???Ricosheet???, a top sheet with dense, low pimples, and an extremely thick sponge. In…

[Column] The “Magic Racket” and the Birth of Modern Regulations

Today, it may sound unbelievable, but in the 1950s there was a period when rackets covered only with sponge dominated the sport.
These rackets did not use the rubber top sheets found on modern inverted rubbers.

１．The “Explosive Power” That Shocked the World

The story began at the 1952 World Championships in Bombay.
Japanese player Hiroji Sato won the world title in his very first appearance using a sponge racket nearly 10mm thick.
Compared with the hard rubber rackets commonly used at the time, the speed and power were overwhelming.
Another unusual feature was the almost silent sound at impact.
Opponents struggled to read the ball’s speed and spin, leading people to call it a true “Magic Racket.”
The incredible performance of this racket shocked the global table tennis community.

２．Ichiro Ogimura and Japan’s “Golden Age”

One of the most important figures in the history of sponge rubber was Ichiro Ogimura, later known as “Mr. Table Tennis.”
Rather than treating sponge rubber as a simple gimmick, Ogimura developed advanced tactics that fully utilized its unique characteristics.
By winning the Men’s Singles titles at the 1952 and 1956 World Championships, he helped establish Japan’s “Golden Age” in table tennis.
However, sponge rubber became so dominant that it began to change the nature of the sport itself.
Its combination of silent impact, extreme speed, and unpredictable ball behavior created major concerns within the table tennis world.

３．Why Was “Sponge Only” Banned?

In 1959, international table tennis regulations were revised, and sponge-only rackets disappeared from official competition.
Several major concerns led to this rule change.

Excessive Power
- With sponge thickness reaching nearly 10mm, rallies became extremely difficult to sustain.
Changes to the Nature of the Sport
- Because the impact sound was extremely quiet, players could no longer judge spin or speed accurately.
- This was considered harmful to the fairness of competition.
Impact on Television and Spectators
- As television broadcasting expanded, concerns grew that extremely short rallies would reduce the entertainment value of matches.

４．The Ban on “Sponge-Only” Rackets

The 1959 rule revision introduced two major regulations that still influence modern table tennis equipment today.

Sponge Cannot Be Used Alone
- If a sponge layer is used, it must be covered with a rubber top sheet.
- This applies to both inverted and pips-out rubbers.

The “4.0mm” Thickness Limit
- For sandwich rubbers (top sheet + sponge), the total combined thickness must remain within 4.0mm.
This regulation continues to shape modern rubber design today.

Hard rubber sheets without sponge are treated differently.
- Their maximum thickness is limited to 2.0mm.

In simple terms, the rules were redesigned so that powerful sponge technology could only be used under strict thickness limitations.
Modern “thin top sheet × thick sponge” designs are ultimately built within this regulatory framework.

My Favorite Book: Ping Pong San — The Roots of Passion

While discussing the history and evolution of table tennis equipment, I would also like to introduce a book that has left a deep impression on me.
That book is Ping Pong San by Mitsuru Jojima (Kadokawa Bunko).
The book explores the extraordinary passion and philosophy of Ichiro Ogimura, the legendary figure known as “Mr. Table Tennis.”
Through this story, I realized that Ogimura was far more than just a world champion.
He devoted himself not only to winning, but also to spreading friendship and peace through table tennis across national borders.
Behind every evolution in table tennis equipment lies the passion of players and innovators who constantly pushed the sport forward.
This book beautifully explains the human passion that exists behind the strict 4.0mm equipment regulations we still follow today.
For anyone who truly loves table tennis, this is a book I sincerely recommend.
For me personally, it represents one of the deepest roots of my passion for the sport.

Book Information: Ping Pong San

Title: Ping Pong San (Mr. Ping Pong)
Summary: A biographical non-fiction book about Ichiro Ogimura, the legendary “Mr. Table Tennis,” who connected people and nations through the sport.
Availability: Currently available only in Japanese, but highly recommended for readers interested in the history and philosophy of modern table tennis.

Note to International Readers

Even for readers outside Japan, it offers a deeper understanding of the culture and passion behind modern table tennis.
Please note that the link below directs to Amazon Japan.
The book is currently available only in Japanese.
However, for table tennis enthusiasts, it remains a valuable book from both a historical and philosophical perspective.

リンク

５．Finding the “Ideal Hardness” for You

To produce high-quality shots, the ball must sink into the rubber properly during contact.
A good rubber should help you balance the three key elements of table tennis:
- speed
- spin
- control

The Relationship Between Swing Speed and Ball Sink

Top players can successfully use extremely hard rubbers because their high swing speed forces the ball deeply into the sponge.
However, swing speed and physical power vary greatly from player to player.
Because of this, there is no single “correct” hardness that works for everyone.
The most important question is whether your own swing can consistently make the ball sink into the rubber.
If the ball cannot sink properly into the sponge, it becomes difficult to generate stable spin and control.

When in Doubt, Start Slightly Softer

Instead of immediately choosing an extremely hard rubber, it is often better to begin with a slightly softer one.
A softer rubber makes it easier to feel the ball sink into the sponge during contact.
This helps improve consistency, spin generation, and overall control.
As your technique and swing speed improve, gradually increasing hardness is often the safest path to long-term progress.

My Personal Example: Apollo 5 (Yinhe)

I personally use the Chinese rubber “Apollo 5” on the forehand side of my Chinese penhold racket.
This rubber is available in several hardness options, including 36, 38, and 40 degrees.

40 Degrees
- For my swing speed, the sponge felt too stiff.
- The ball did not sink deeply enough into the rubber, making spin generation difficult.
38 Degrees
- This hardness provided the best balance for my playing style.
- The impact feel was easier to control and more comfortable during play.

Since the 38-degree version already felt ideal for me, I have not tested the 36-degree version.

The author chose the 38-degree version of the Chinese rubber “Apollo 5” for personal use.

６．Summary

In this article, we explored the often misunderstood reality behind rubber hardness.
The most important points are summarized below.

Most catalog hardness values represent only the hardness of the sponge itself.
Even with the same hardness number, top sheet structure can dramatically change the actual feel.
Hardness numbers cannot be directly compared across brands because measurement standards differ by manufacturer.
Modern thin-sheet rubbers often feel softer and provide more ball bite than their hardness numbers suggest.
Choosing a hardness that allows the ball to sink properly with your own swing is the key to improvement.

Finding the ideal rubber can sometimes feel difficult. However, experimenting with equipment is also one of the great joys of table tennis.
Modern rubbers continue to evolve through advanced designs such as “thin top sheet × thick sponge” structures. Because of this, manufacturer specifications should be viewed as general guidelines rather than absolute answers.
Understanding structural differences and measurement standards can greatly reduce the risk of choosing a rubber that does not suit your playing style.
In addition to hardness, sponge thickness is also an extremely important factor in rubber selection.
Please also check the related article below for a detailed explanation of sponge thickness selection.
I hope your future equipment choices become both more enjoyable and more satisfying.