professional players. For many years, it was customary for fielders to leave their gloves on the field when their team went in to bat. This practice was prohibited by the major leagues in . Baseball gloves have grown progressively larger since their inception. While catching in baseball had always been two-handed, gloves eventually grew to a size that made it easier to catch the ball in the webbing of the glove, using the off-hand to keep the ball from falling out. A glove is typically worn on the non-dominant hand, leaving the dominant hand for throwing the ball; for example, a right-handed player would wear a glove on their left hand. The shape and size of the baseball glove are governed by official baseball rules. Section 3.00 - EQUIPMENT AND UNIFORMS specifies glove dimensions and materials in parts 3.04 through 3.07. Modern day The structure and quality of the baseball glove have developed greatly over the past century. Today, the production of baseball gloves is much more precise and efficient. This has greatly increased the usefulness and accessibility of baseball gloves to the general population. Currently, Easton is "experimenting with combining leather and Kevlar (used in bullet-proof vests) in a new ultra-lightweight glove line". Manufacturers have also designed new, non-traditional types of gloves to suit non-traditional players. Also, manufacturers are personalizing gloves for high-caliber players to help increase their exposure on national television. Although there have been numerous advances in baseball glove design, the greatest arguably came with the advent of the catcher's mitt. Yet despite state-of-the-art mitts being used by catchers, a Wake Forest University study of 39 U.S. minor-league players demonstrated that the mitts still do not offer enough protection from hand and wrist injuries. The highest-quality baseball gloves are typically made of heavy leather. These heavy leather gloves usually take more time for the player to break in. They also provide a tighter, more personalized fit for the player. This is an improvement from youth and recreational gloves, which tend to feature palm pads and/or adjustable Velcro wrist straps. These gloves take less time to break in or are pre-broken in, are less personal and more "one size fits all". Varieties Baseball gloves are measured by starting at the top of the index finger of the glove and measuring down the finger, along the inside of the pocket and then out to the heel of the glove.