Tennisbälle

Tennisbälle are the spherical projectiles used in the sport of tennis. They are typically yellow-green in color, a hue chosen for its visibility against various court surfaces and backgrounds. The official size and weight of a tennis ball are regulated by the International Tennis Federation (ITF) to ensure consistency and fairness in play. A standard tennis ball has a diameter between 2.57 and 2.70 inches (6.54 and 6.86 cm) and weighs between 1.974 and 2.094 ounces (56.0 and 59.4 grams).

The construction of a tennis ball consists of a rubber core, which is pressurized to give it bounce. This core is then covered in a felt material, usually wool or a synthetic blend. The felt affects the ball's aerodynamics, slowing it down in flight and allowing for spin to be applied by the player. The pressurization of the ball is crucial for its performance, as it dictates the height of its bounce. Balls are typically sold in pressurized cans to maintain their bounce. Unpressurized or "pressureless" balls are also available, offering a more consistent bounce over time but generally feeling harder and heavier.

Tennis balls undergo rigorous testing to meet performance standards, including bounce height, deformation, and colorfastness. Over time and with use, the felt on a tennis ball wears down, and its internal pressure can decrease, leading to a loss of bounce and a change in its playing characteristics. This is why players regularly replace their tennis balls during matches and practice sessions. The development of tennis balls has seen innovations aimed at improving durability and performance, including different felt compositions and core designs.