One good thing to study is finishing for auto-body, and the main lesson from it is having the smoothest surface possible before any finish is applied.
In woodworking, most will stop at 400 grit, and some below, but if you take a close look at those stocks, even factory stocks, you can see faint sanding marks, (look at it with a magnifying glass of low power). Thus, the higher in grit you go, the smoother the surface, and its easier to get that slick finish. After using 600, though, the wood seems smooth enough that you don't see these.
I would say that grit screen cloth acts somewhat like Scotch Brite pads, as the screen allows the whiskers to stick through the holes in screen itself. Plus, the screen is made from round fibers, the same as the screen in a window, so it's never flat like regular sand paper.