There are two main types of materials used to make soccer balls: PVC (Poly Vinyl Carbonate) and PU (Polyurethane).
PVC is more affordable and can be more durable than PU. Scuff-resistant PVC is generally used in training soccer balls. PVC is also used in indoor soccer balls, futsal balls and street soccer balls. PU is usually reserved for higher end match balls and premium match balls. A PU soccer ball is often softer than a PVC soccer ball. PU tends to have a better responsiveness off the foot. Note, all PU and all PVC soccer balls are not the same, there are different levels in quality of both PVC and PU and different ball construction techniques.
Glossy coatings are often used to aid in reducing water absorption and scuffing on softer PU soccer balls.
Material thickness plays a vital part in the quality of hand-sewn soccer balls. Multiple layers of lining are placed between the cover and the bladder. These layers are composed of polyester and/or cotton bonded (laminated) together to give the ball strength, structure and bounce. Professional soccer balls usually have four or more layers of lining. Promotional or practice balls are often constructed with less layers of lining. The lining helps the ball retain it's shape and bounce over the life of the ball.
Many soccer balls include a foam layer for added cushioning and ball control.
The bladder is the component that holds the air, usually made from rubber, latex or butyl. Compared to latex bladders, butyl bladders retain air for longer periods of time. Latex bladders tend to provide better surface tension. Butyl bladders however offer the excellent combination of contact quality and air retention. Futsal ball bladders are filled with foam to limit the bouncing capability of the ball since they are used on a hard flooring.
Natural Latex Rubber bladders offer the softest feel and response, but do not provide the best air retention. Micro pores slowly let air escape. Balls with natural rubber bladders need to be re-inflated (at least once a week) more often than balls with butyl bladders (stay properly inflated for weeks at a time). Some balls use carbon-latex bladders in which the carbon powder helps to close many of the micro pores, helping keep latex soft response and bounce.
Rubber bladders offer an excellent combination of feel and air retention and can be found in most recreational balls.
Most balls use butyl valves for air retention, with higher end balls using a silicone-treated valve for superior performance. Silicone treated valves are used on some balls for smooth insertion of the inflating needle and added protection from air loss. When you first receive a ball, a good idea is to put a few drops of silicon oil in the valve. This will provide easier needle insertion and better air retention.