There are two areas on my bow arm that need protecting, my forearm and my index finger. All archers are vulnerable to string slaps which hurt and leave a nasty bruise so there are lots of arm guards and bracers available on the market that protect the forearm. Modern bows have an arrow ledge which protects the shooters hand so most archers don't need anything on their hand. I shoot a primitive bow with no ledge so the arrow crosses the top of my hand and sometimes the fletching (which is stiff and sharp) cuts me. There are gloves available that protect that part of the bow hand but I couldn't find anything that was both pieces on one so I designed and made my own! (This is a common theme in my life.)
The added bonus of making my own is that I got to pick out my own leather and make it as fancy as I wanted. That's embossed cowhide, not actual crocodile in case you were wondering.
And most importantly it does exactly what I need it to. After three hours of shooting on Sunday I came home bruise and cut free!