Usually, a combination of four different materials are used to step up the standard of comfort and durability. A blend of polyester, nylon, rayon and elastic create soft comfort. The foam padding it thick, but not bulky, as in the earlier style of pads.
The wonder fabric of the latter part of the century has found its way into the manufacture of baseball equipment as well. That being the ultra breathable and lightweight neoprene. Inside grippers provide no slip traction, from the inside, which is a detail you’ll want to check for as well.