Table tennis balls

The table tennis ball, or ping pong ball, is a crucial piece of equipment in the sport of table tennis. It is a hollow sphere, usually made of plastic or celluloid, and is designed to be lightweight and durable. The standard size is 40mm in diameter, though older balls were sometimes 38mm. The weight is consistently around 2.7 grams.
The color of the ball is typically white or orange, with white being the standard for tournament play and orange often preferred for casual games due to its visibility in various settings. The outer surface is matte, which helps to reduce glare and improve visibility.
Table tennis balls are rated with a star system, with 1-star balls being softer and more prone to breaking, while 3-star balls are the most durable and approved for official competitions. The International Table Tennis Federation (ITTF) also approves specific balls for use in their sanctioned events, and their approval stamp is usually printed on the ball.
The introduction of the 40mm ball and the shift from celluloid to plastic materials have been significant changes in the history of table tennis, impacting the game’s dynamics and play style