I just got my book that I ordered through Amazon titled, "Zinn and the Art of Mountain Bike Maintenance" by Lennard Zinn, for ~ $16.50 (free shipping).
I started to read it from the beginning. I'm in the chapter on tools, level 1. One of the items that he recommends, but doesn't explain why is that for a patch kit, he prefers one w/ sand paper instead of a metal scraper.
Does anyone know why he would say so? How about you? Have you found a difference in the ease of patching a tire (and it not exploding or losing the patch) with either material?