This^^^^ sharpie on blades also protects them from rusting if exposed to wet weatherOn a related note, I always use a black Sharpie to cover my broadheads; they are like a mirror in the sunlight, otherwise.
I watched my hunting partner leave on a stalk and I could see his bow glimmering in the sun. That is when I started painting. After the fact I noticed that randy ulmer paints his bow. So if the mule deer master does it, it can't hurt.