DrJSquared

I've seen people on the internet use a grooving tool before chiseling the stitching holes and I've seen them make a crease either with a tool or dividers. If I'm making things like book portfolios and knife sheaths, I don't think cutting the leather with a grooving tool is going to hurt it strength wise. Is there a preference of one technique over the other or a reason I might put a crease in vs a cut groove? Thank.

I have a stitch punch set that has one with maybe 5 tines, 4 tines, 2 tines, and 1 tine. I was punching through two layers and the punches get stuck in the leather. They have this coating on them to protect them from rust I suspect but I'm guessing that is the cause of the grip with the leather. I've noticed a couple of videos where other's punch set appears polished. Does that prevent getting stuck in the leather and if so, what did you use to polish them?