Why Are Tennis Balls Fuzzy?

Even for people who don’t play tennis, everyone is familiar with what a standard tennis ball looks like. It’s a bright, fluorescent yellow that might seem like a normal ball from afar, but it’s also covered with this fuzzy, felt substance that a lot of people take for granted.

Why are tennis balls fuzzy? The fuzzy felt on tennis balls helps to slow the ball down and provides a very uniform bounce on different surfaces. It also grips the string much better than a basic rubber ball could. Finally, the extra layer of coating adds durability to the tennis ball that it wouldn’t otherwise have.

Introduction of Fuzz on Tennis Balls

To understand how tennis balls became fuzzy, it’s important to look at the history of not only tennis, but the ball. In the early days, the sport of tennis did not have any type of uniform ball to go with.

Materials like sheep stomach, human hair, animal fur, and more all showed up in balls at one point. Once the sport became a little more modernized, it was clear that it needed a standard.

Another major breakthrough with tennis balls came when Charles Goodyear invented vulcanized rubber. It was officially patented in 1844, so when lawn tennis took off a few decades later, there was an easy-to-produce ball that was durable and consistent. The most obvious difference then was that the tennis ball still didn’t have any type of covering.

The Science Behind Fuzz On Tennis Balls

Pressurized air fills a tennis ball, and it has a hollow rubber core. If a person cuts a tennis ball open, it’s easy to see that there is not a lot to a tennis ball overall. That rubber core has woven wool felt covering it, which is meant to delay flow separation, as well as provide an extra layer of protection for balls to perform as expected.

Felt also helps with aerodynamic drag, which means that the ball travels as a player expects, and it bounces off the different surfaces the right way. Even though certain surfaces do affect the balls in different ways, it is not as crazy as a ball without felt would be. The felt and fuzziness also determine how fast the ball goes.

Think about just how challenging it would be to learn how to play tennis with balls that play vastly differently all the time. No one wants to deal with that. A fresh can of balls is going to perform roughly the same way, every single time when used in similar weather conditions and playing surfaces.

Since balls start to lose their bounce right after opening, the felt doesn’t have to be that durable. If tennis balls were refillable with air time and time again, companies would opt for a different out cover.

The Making Of The Modern Fuzzy Tennis Balls

The modern tennis ball didn’t start to take its shape until the 1920s, when sealed shut cans to keep them pressurized. They would originally be in a metal tube, and a church key was needed to open the top of the can.

Watch any old video clips of tennis played back then, and it’s easy to see that people did use balls that look mostly the same as today.

The one difference that is easiest to spot? The balls were not fluorescent yellow until the 1970s. Television started to take off then, and people realized that it was easier to see the ball not only in person, but on the screen as well.

Felt in a fluorescent yellow (officially called optic yellow) is not only easy to see on television, but players noticed an improvement over white balls soon after they first appeared. It helped out a lot in all types of weather conditions, as well as different times in the day. Nobody wants to be struggling to see the ball at a major event, and the yellow just makes sense.

All tennis balls in the present form have to hold up to strict standards set by the International Tennis Federation. The diameter must be 2.57 to 2.70 inches, and the mass must be between 1.98 and 2.10 ounces.

Only yellow and white balls are approved, but most people will notice that virtually every tennis ball these days is yellow. This is because professional players are very reluctant to change, so no tournament director is going to mess with things in the middle of the season.


High-quality woven felt is used on all top tennis balls. It is made up of about 2/3 wool and 1/3 nylon. The nylon is in there to help with overall performance.

There are two panels of felt added to each ball, and they are roughly 2 inches wide by 6 inches long. A lot of times, these panels are referred to as “dog bones” because of their overall shape.

Off the assembly line, tennis balls are not exactly that fluffy. They can seem extremely matted and a bit tough to handle. That is why balls are usually placed in an industrial-sized washing machine. They are referred to as fluffers in the tennis world, and they get a steam atmosphere that makes the felt return to a more natural state.

Once everything is good and back to normal, it’s time to do the final prints on the tennis ball depending on the brand. Then, they are bottled up in a pressurized can at around 12 to 14 PSI so they are ready to go for consumers.

As for the felt and fuzz, a ball gets thrown out if it becomes too fuzzy during play. At the professional level, that very rarely happens, simply because they change out balls so frequently. Casual players might find balls fluffing up a little too much at some point, but most will just continue to play with them if possible.

You can read more about what tennis balls are made of in this post.

Different Tennis Balls = Different Fuzz

When it comes to comparing performance tennis balls, the two main types are regular duty and heavy-duty. They might look pretty close to the same exact thing, but there are subtle differences in fuzz that make a fairly big difference.

Regular Duty

A regular duty ball is made for clay courts, and since the court is softer, it doesn’t require the same amount of fuzzy felt covering the ball. It’s a little thinner, keeping clay from sticking to the ball. Clay court balls are much less likely to fluff up, although it does happen on occasion.

No matter how hard a person tries, a clay court ball is going to get dirty. A regular-duty ball just does a much better job of handling the surface.

Heavy Duty

On hard courts, heavy-duty balls are the way to go. They have more fuzz on them, and as the name implies, they can take more abuse before looking dirty and not bouncing much. They are built to hold up even after hours of hitting on a hard, gritty surface.

This is a ball that performs very well on hard courts, but it might struggle a bit when used on clay. Mainly, the fuzz on the ball is a bit fluffier, which means it could become extremely fluffy if the conditions are a certain way. It’s meant to handle a harder surface, so stick with the right type of wall if possible.

The Future Of Fuzzy Tennis Balls

In some ways, it’s a bit remarkable that technology or some type of breakthrough hasn’t changed the tennis ball since the 1970s. Many will say that if it isn’t broke, don’t fix it. However, tennis balls become too fuzzy at times, and they still go dead faster than most people would like.

There is also the issue of being eco-friendly. While a lot of tennis balls are reused and recycled, the entire package has always been somewhat of an issue. Wilson’s latest release of the ball they call Triniti is looking to change that, as it is the first performance ball that uses fully sustainable packaging.

At some point, we will see the evolution of the tennis ball, and in particular, the fuzzy felt that goes on the outer shell. For now, players pretty much know just how long a can of balls are going to last before they get too fuzzy and/or dead to hit.

Similar Posts

Leave a Reply

Your email address will not be published. Required fields are marked *