hardwares stores sell small circles of tan colored felt padding which I have used under furniture as padding to prevent scratches. The brand name is 'Felt-Gard'. Last month I found that this comes in 4" x 6" sheets.
I've cut pieces to fit under my index finger and it works quite well. One side has adhesive which helps keep it in place.
upholstery shops also have high quality felt padding in several different thicknesses. They usually have left over scraps which are big enough for gloves.
This stuff looks like what you would find in upholstery. I'll start there. I've a nice Santo endorsed 70's glove that had the padding removed in the palm and it won't hold its shape. I also find that some 1st base gloves lack enough padding.