The tennis ball is arguably the most important piece of tennis equipment. After all, without good tennis balls, there is no game! This article will share some of the frequently asked questions that players have about tennis balls.
What color is a tennis ball and why?
The tennis balls used at major sporting events are almost always fluorescent yellow. Officials have chosen this color because it is very easy for the human eye to track at high velocities. Recreational tennis balls can any color.
How big is a tennis ball?
According to the International Tennis Federation, the standard size of a tennis ball is
between 2½ inches (6.35cm) and 2 5/8 inches in diameter. This is one of the oldest tennis ball specifications, dating back to 1880.
What is the mass of a tennis ball?
According to the United States Olympic Committee, a tennis ball should weigh between 2 and 2 1/16 ounces (57.7 and 58.5 grams). The International Tennis Federation agrees, saying that all tennis balls used in their tournaments should be between two ounces (56.7 g) and 2 1/16 ounces (58.5 grams) in weight.
How many types of tennis balls are there?
There are three main classes of tennis balls:
- Professional tennis balls
These are premium, high-quality balls with excellent durability. They are used in professional tennis tournaments.
- Championship tennis balls
Championship balls are a small step down in terms of quality. They might lose pressure more rapidly and the felt isn’t as robust. They are still great tennis balls and ideal for amateur competitions.
- Practice tennis balls
Practice balls are not high performance but are designed to last a long time. There are both pressured and pressure-less practice balls available. The pressure-less balls are very dense and tough. If you are using a tennis ball machine (like these) you want pressureless balls.
How are hard court tennis balls different to clay/grass court?
The only difference between hardcourt and clay or grass tennis balls relates to the quality of the felt. Hardcourt balls will have thicker felt that is made from a combination of nylon and wool. It also has a looser weave than soft-court balls. The thick felt on hardcourt balls doesn’t wear away as quickly, which helps the ball retain its flight characteristics for a longer period.
The tighter weave on clay/grass balls means they will pick up less clay and dirt when hitting the court surface. This stops the balls from accumulating debris and becoming heavier during the game. The tighter weave also means the balls can move faster through the air, which is useful on soft court surfaces where there isn’t as much bounce.
Do tennis balls have different speeds?
Yes! The International Tennis Federation has defined three types of officially sanctioned balls:
- Type 1 — a slightly faster ball that can be used on ‘slower’ court surfaces like clay and grass. It has less felt than a type 2 ball. Also called regular duty tennis balls.
- Type 2 — the standard tennis ball, designed for use on outdoor hard courts. Also called extra duty tennis balls.
- Type 3 — a larger, slow-speed ball that is specifically designed to be used at high altitude.
If you are an amateur player, chances are you will mostly use Type 2 balls. You can view a full list of officially sanctioned balls here.
Do female professional tennis players use different tennis balls to males?
Surprisingly, the answer is usually yes. Female tennis players often use a “faster” ball in competitive matches. This allows them to play an aggressive style of tennis because each shot will move at a faster velocity. Men use a slower ball to slow the pace of those big serves and make the gameplay more varied.
The key difference between fast and slow is how much felt the balls have on them. A ball with less felt will move faster through the air, while the opposite is true for balls with more felt. A ball with more felt will also contact the strings for a longer period, making it “feel” heavier to the player when they play a shot.
In the U.S. Open, women will use regular-duty felt Wilson Balls, while men will use the fluffier extra-duty Wilson balls. The balls have the same size, weight, bounce, and pressure — but they travel through the air at different speeds and feel different to hit because of the differences in felt.
The difference in regular-duty and heavy-duty balls is obvious to professional tennis players who spend many hours on the court. However, amateur players might not even notice the difference between faster and slower balls.
It’s important to note that women don’t always use a different ball. All players competing at the Wimbledon Championships will use the same ball type (regular-duty).
How far should a tennis ball bounce?
All regulation tennis balls should bounce between 135-147 cm (53-58 inches) when dropped from a height of 254 cm (100 inches). Type 3 (high altitude) tennis balls should bounce 122-135 cm (48-53 inches).
How do they make tennis balls?
The process for making tennis balls usually consists of several stages:
- Crushing – The raw materials that make up the ball are crushed together. Most tennis balls use a rubber combined with materials like clay to deaden the bounce of the ball slightly.
- Compressing – The rubber compound is sliced into smaller sheets and compression moulded into the shape of a semi-sphere.
- Sheeting – The semi-circles are removed from the mould tray and left to cool.
- Glueing – Each semi-sphere is cut to an exact height, then has its edges covered in heat activated adhesive. Then, the two shells are injected with compressed air and glued together under heat and high pressure.
- Buffing – The balls are abraded with sand-paper to create grooves that help the felt adhere to the surface.
- Felting – The balls are covered in glue, then covered in felt. Heat and pressure are applied again to ensure the glue is set.
- Packaging – The balls are branded and package in pressurized cans so the balls retain their pressure during transit.