And Jimmy brings up a good point. That isn't to say that they won't work at all any other way. Over time will naturally become burnished with use unless the surface is refreshed. Some folks don't like them burnished (they do cut slower this way) and prefer to keep the surface roughed up with a DMT or similar to maintain a balance of speed and edge quality.

All in how you want to use it and what you want to get from it I guess.