section: Playing equipment
question: How much do squash balls weigh?
article: Squash (sport)
candidates: Standard racquets are governed by the rules of the game. Traditionally they were made of laminated wood (typically ash), with a small strung area using natural gut strings. After a rule change in the mid-1980s, they are now almost always made of composite materials or metals (graphite, Kevlar, titanium, boron) with synthetic strings. Modern racquets have maximum dimensions of 686 mm (27.0 in) long and 215 mm (8.5 in) wide, with a maximum strung area of 500 square centimetres (90 sq in), the permitted maximum weight is , but most have a weight between 90 and 150 grams (3–5.3 oz. Squash balls are between 39.5 and 40.5 mm in diameter, and have a weight of 23 to 25 grams. They are made with two pieces of rubber compound, glued together to form a hollow sphere and buffed to a matte finish. Different balls are provided for varying temperature and atmospheric conditions and standards of play: more experienced players use slow balls that have less bounce than those used by less experienced players (slower balls tend to "die" in court corners, rather than "standing up" to allow easier shots). Depending on its specific rubber composition, a squash ball has the property that it bounces more at higher temperatures. Squash balls must be hit dozens of times to warm them up at the beginning of a session; cold squash balls have very little bounce. Small colored dots on the ball indicate its dynamic level (bounciness), and thus the standard of play for which it is suited. The recognized speed colors indicating the degree of dynamism are: ::::: Some ball manufacturers such as Dunlop use a different method of grading balls based on experience. They still have the equivalent dot rating, but are named to help choose a ball that is appropriate for one's skill level. The four different ball types are Intro (Blue dot), Progress (Red dot), Competition (single yellow dot) and Pro (double yellow dot). The "double-yellow dot" ball, introduced in 2000, is the competition standard, replacing the earlier "yellow-dot" ball. There is also an "orange dot" ball. Players wear comfortable sports clothing. In competition, men usually wear shorts and a t-shirt, tank top or a polo shirt. Women normally wear a skirt or skort and a t-shirt or a tank top, or a sports dress. The National Institutes of Health recommends wearing goggles with polycarbonate lenses. Many squash venues mandate the use of eye protection and some association rules require that all juniors and doubles players must wear eye protection.