What Are Baseball Bases Made Of?

Not-so-soft Bag

    The Major League Baseball rulebook states that bases must be white, 15 by 15 inches, covered in canvas or rubber, 3 to 5 inches tall, filled with soft material and attached to the ground. Bases are a few inches tall around the perimeter and domes slightly to a maximum height. They are heavy, filled with a thick rubber and covered with a synthetic, striated white coating that does not puncture under the weight of metal spikes. The middle of the underside contains a protruding metal nub that interlocks with a permanent metal-lined hole on the field.

Baserunner Beware

    The rubber on a base has very little give, feeling more like hard vinyl. Moreover, the bases don't move once anchored to the ground. This sets up runners for ankle sprains, knee injuries, torn ligaments, dislocated fingers and shoulders, and broken bones if they make contact with the base awkwardly..

About the Author

Christopher Michael began writing in 2010 for Break.com. He received a Bachelor of Arts in English from the University of Massachusetts, Amherst. Writing sports and travel articles helps support his professional baseball career, which has taken him to 49 states, five continents and four oceans.