What is a Football?

Often called a 'pigskin,' the odd-shaped ball is actually made of cowhide today.

Football on reflection
Andrew Unangst/Photographer's Choice/Getty Images

A football, which is used in the sport of American Football, is an elongated inflated rubber bladder that tapers to a point at each end. Despite often being referred to as a pigskin, a football is actually covered with pebble-grained leather or cowhide. White laces are sewn on one side of the ball to allow the passer to get a better grip on it.

Shape and Size

Unlike the balls used in most sports, a football is not spherical in shape, so there is more of an unpredictability in the way it bounces.

When thrown, ideally the ball leaves the hand spinning in a spiral motion, which keeps the flight of the ball more aerodynamic.

There are different sizes of footballs, with smaller versions available for youth play. At the NFL level, the ball measures from 20 3/4 to 21 1/4 inches around its middle, 28 to 28 1/2 inches around its ends and 11 to 11 1/4 inches from tip to tip.

Inflation Level

The football also weighs between 14 and 15 ounces and is inflated to between 12 1/2 and 13 1/2 pounds per square inch. The inflation level of footballs is important. During the 2014-2015 NFL playoffs, most of the balls used in the first half of a game between the New England Patriots and the Indianapolis Colts were found to be about 2 pounds under the minimum required inflation level. A complaint from the Colts prompted the referees to test inflation levels and investigate. 

The Patriots, who were hosting the game, received some blame for the underinflation.

The issue even sparked a controversy called "Deflategate," and quarterback Tom Brady eventually received a four-game suspension because the NFL found that Brady may have known about the underinflation. 

History

When football was in its infancy, a pig's bladder was often inflated and used as the ball.

"It may surprise you to learn that footballs were originally inflated with the bladders of animals, including those from swine," notes Big Game Sports, a company that manufactures footballs. "In later years, these animal bladders were placed inside a leather cover, giving rise to the term 'pigskin'."

After Charles Goodyear invented vulcanized rubber in 1844, manufacturers began using the new material to make footballs -- and players tossed their pigskins and replaced them with the rubber versions. Today, "though they are still called 'pigskins,' ... all pro and collegiate footballs are actually made with cowhide leather. Recreational and youth footballs, on the other hand, are often made with synthetic material or vulcanized rubber." (Big Game makes its own footballs with cowhide by the way.)

So, next time you're ready to toss that perfect spiral, remember that the "pigskin" you're holding isn't actually a pigskin, but the ball did travel a long way before eventually taking on the shape, inflation level and material of the football you're holding in your hands.