The covers of today's golf balls are made of numerous different materials such as Balata, Surlyn, Zylin, and Elastomer.
Balata is a type of natural rubber and is the softest of all other cover types.
Surlyn, which was the first and most durable cover material that revolutionized the construction of the golf ball when it was introduced 20 years ago, is a trade name for a group of thermoplastic resins developed by the Dupont Corporation. Most golf ball manufacturers of durable covers use either Surlyn or a similar material blend. The emphasis today is to provide both durability and feel. With all other aspects of construction being equal, a balata-covered ball will spin easier and is preferred by players who demand maximum feel and control. This means more control over shots where the action of the ball is critical.