Leather can be cleaned with Saddle Soap, and then treated with Pitch Blend, Bee Natural or another leather conditioner to prevent drying and becoming grooved and stiff. The nylon is usually sewn to soft leather and if not kept clean will need to be replaced. Cordovan is nice when new but will harden fairly soon unless cleaned and treated. They are pretty much a draw in my mind. Another option is the leather glove with an insert made by/for Howard Hill. He used whale bone, but I think the company is using a plastic insert. It has two layers with an inner soft liner and flexible insert to prevent grooving. This glove is used for heavy weight bows over 70 lbs. The few I bought needed to be tightened by adding a thin layer of leather inside along the top side to keep them on my fingers. I also added leather stitching below the original stitching to pull it tighter. IMO tabs are ok for some, but generally inconvenient if you are trying to get off a quick shot. I used them for target shooting years ago, and most were a cordovan, and some had a rubber spacer to prevent pinching the arrow when drawing.