Today’s tennis balls are made of a hollow, two-piece rubber shell filled with pressurized gas. The rubber shell is covered with felt made from nylon or wool. The International tennis federation, ITF states that tennis balls should be between 2 1/2 and 2 5/8 inches in diameter and weigh between 2 and 2 1/16 oz. The felt used to cover tennis balls destined for official play is bright yellow.
RS is only working with the finest felt types available on the market.
Balls which haven’t got enough pressure inside make a thud when they hit the floor. These are called dead balls.
RS Tennis and other tennis ball manufacturers mold rubber into two shapes that are pressed together to form the core of a ball. To achieve an appropriate level of bounciness, tennis ball makers inject a specific amount of pressurized air into the center of each rubber core. Manufacturers buff the sealed, pressurized rubber balls and cover them in glue. Machines cut long pieces of bright yellow felt into two shapes that are wrapped around each tennis ball to form a covering. Ball makers heat the completed tennis balls to make the glue form a seal that holds the two pieces of fabric together.
The ITF states that tennis balls must bounce between 53 and 58 inches high after being dropped onto a concrete floor from an elevation of 100 inches. To achieve this precise bouncing height, tennis ball makers add a very specific amount of air to the core of tennis balls. In general, tennis balls are pressurized to 12 pounds per square inch.