Leather Grades used in Baseball & Softball Gloves:
Buffalo Skin
Buffalo skin is used by only one manufacturer, Nokona. Buffalo skin is said to be tougher and lighter than full grain steer hide, but breaks in just as easily. Most people aren't going to want to get a Little Leaguer a buffalo skin glove because of the high price, but if they want to, it's out there.
Full Grain Leather
"Full-Grain" leather is steer hide or cow hide leather on which the entire natural grain remains. It will either be the original thickness of the skin, or the bottom grain will have been sanded off until the leather is the desired thickness. This grade is uncommon in youth gloves, but is readily available in premium adult gloves that come in sizes suitable for older Little Leaguers. Although in theory full grain leather can be any weight, in practice, gloves made of full grain leather tend to be stiffer and heavier than other types, and require longer break-in periods. These leathers are rarely pre-oiled, because the players who buy gloves of this quality usually want to apply their own particular break-in method. Once broken in, full grain leather gloves are superior in both performance and durability. Catchers' mitts are almost always made of full grain leather or premium steer hide.
Top Grain Leather
"Top-Grain" leather" is a misnomer; it is usually leather in which the "top" grain (the fur side) is sanded off until the leather is a desired thickness, and then filled or treated, where an artificial grain is introduced, usually by pressing. Many baseball gloves probably are top grain leather, but the manufacturers may not always use the phrase to describe the leather. Often they use a brand name instead. Nokona is the only manufacturer that says its gloves use "top grain leather." In Nokona's case, the leather is heavy weight and very durable. Wilson's "Quick-Stop" leather is also a top grain leather, but it is medium weight and has average durability.
Premium Steer Hide
Steer hide, which comes from neutered bulls, is somewhat stronger than cow hide. Manufacturers are free to call any steer hide "premium," but in practice they reserve this designation for their better grades of heavy weight steer hide, usually top grain, occasionally full grain. Gloves made of this leather tend to be stiff and somewhat heavy, with longer break-in periods. These leathers are sometimes pre-oiled. Many manufacturers have gone away from premium steerhide both because the market now demands softer gloves, and to save money because few consumers know the difference.
Leather or Cow Hide
"Leather" means cow hide, usually medium weight, but sometimes heavy weight. This category encompasses the greatest range of quality. Cow hide performs well, and will break in faster, but also wear out faster than steer hide. Usually this grade will come "pre-oiled" or otherwise treated to reduce break-in time. Cow hide is probably the best all-around choice for a youth glove for ages 10 and up. There are many good Leather glove bargains in the $25-$50 range.
Kangaroo Skin
Kangaroo skin is stronger than steer hide of any grade, and weighs a fraction as much. It is fairly new to the baseball glove market, and what grades are being used is anybody's guess. Some manufacturers use kangaroo only in premium gloves, while others use it only in their budget baseball gloves. Early reports say it breaks in easily but doesn't hold its shape as well as the better cow hide or steer hide grades. Often gloves are made with steer hide or cow hide palms for durability, and kangaroo skin backs for light weight.
Pigskin
Pigskin is far less durable than cowhide. However, it is more flexible and breaks in far more easily than cowhide, and costs less. Pigskin gloves are inexpensive, and can be ideal for a youngster who wants a good-performing glove but who may grow out of it in a year.