The middle of the ball is cork which is covered with rubber. This cork and rubber center are tightly machine wound with cotton and wool yarn.
A two piece leather cover is stitched together with 108 stitches of waxed cotton yarn.
All balls must pass the established standards for size, weight and shape. They also must be uniformly lively. To insure this, they are tested randomly.
For amateur leagues, the ball cover can be synthetic leather. It is less expensive than cowhide. Raised stitching makes the ball easier to control. They are good to use for instruction.
Rawlings official official league ball costs about $7. It has a synthetic cover and is intended for recreational use.
MacGregor boys practice balls cost about $21-25 for 12 balls. The balls have a synthetic cover and are recommended for youth play.
Rawlings Little League competition grade baseballs cost about $35 for 12 balls. The balls have a leather cover.
Rawlings Major League official game ball made to the exact specifications of Major League Baseball costs about $15 for one ball. You can use it to train like the professionals.