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 1/4 inches in circumference.
(3.02) 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) (Rules 8.02(a)(2) through (6)).
Rule 3.01 Comment (Rule 5.02 Comment): Should a ball come partially apart in a game, it is in play until the play is completed.