Originally Posted by
2knives
I've found that silicon carbide is the best stuff. I've worked for a metallographic institute which required samples of all sorts to be mirror finished in order to be etched to observe the grain structures, and silicon carbide is all that we used. It's very hard stuff and the more you pay for it the better it is attached to the paper. That sort of paper is more expensive but it lasts a long time, especially the higher grits.
What you really want to look at is what material the abrasive is i.e. SiC CrO3 etc., and how it is attached to the backing.
3m is vague on what their material is, i haven't found what it is yet on the auto series of papers "wetordry"... < does anyone know this?