Strings (tennis)
The material used in tennis string can significantly affect a player's performance, and even health. Several materials are used to make tennis strings. They vary in terms of elasticity, durability, rebound efficiency, tension holding capability, and manufacturing cost, among other considerations.
Tennis court
The ITF's Play and Stay campaign promotes playing on smaller courts with slower red, orange and green balls for younger children. This gives children more time and control so they can serve, rally, and score from the first lesson on courts that are sized to fit their bodies. The ITF has mandated that official competition for children under 10 years of age should be played on "Orange" courts long by wide. Competition for children under 8 years is played on "Red" courts that are long and wide. The net is always 0.8 m high in the center.