but it does not keep that "razor edge" that the leek does. For instance, when I open the mail, I find the edge grabs all the time.
Addendum:
Sorry, I forgot to mention that paper and cardboard will blunt just about anything. Its actually as abrasive as a very fine sandpaper.
You can actually strop a knife on cardboard as you would a leather belt. It's also an effective way of getting gunk off the blade.