3.01 The Ball
The ball shall be a sphere formed by yarn wound around a small core of cork, rubber or similar material, covered with two strips of white horsehide or cowhide, tightly stitched together. It shall weigh not less than five nor more than 5 1/4 ounces avoirdupois and measure not less than nine nor more than 9. inches in circumference.
No player shall intentionally discolor or damage the ball by rubbing it with soil, rosin, paraffin, licorice, sand-paper, emery-paper or other foreign substance.
PENALTY: The umpire shall demand the ball and remove the offender from the game. In addition, the offender shall be suspended automatically for 10 games. For rules in regard to a pitcher defacing the ball, see Rules 6.02(c)(2) through (6).
Rule 3.01 Comment: Should a ball come partially apart in a game, it is in play until the play is completed.