Tennis balls

Key Characteristics:

1. Core: The ball consists of a pressurized, two-piece rubber core. This core contains compressed air (or sometimes nitrogen gas) which gives the ball its characteristic bounce and speed.
2. Felt Covering: The rubber core is covered in a synthetic or natural wool felt (usually a nylon/wool blend) which is secured by a strong adhesive. This fuzzy exterior, typically fluorescent yellow, helps to regulate the ball’s aerodynamic properties (reducing speed and promoting spin) when struck by a racket.
3. Bounce: The pressurized core is what gives the ball its high rate of bounce. Over time, or with repeated heavy use, the internal pressure leaks, causing the ball to “go dead,” reducing its bounce and making it unplayable at a professional level.