Re:Professional Knife Sharpening vs. Do It Yourself
I know what Ed means by hardness of knives. I have a vanadium steel knife that I picked up for $20 around 1980 or so from a Japanese store (one in New York). It was my first decent knife, and I stopped using my food processor for slicing after getting it. Fast forward a couple of decades, where wife and Kids used the knife on ceramic plates and glass cutting boards in spite of my begging them not to. I took it to a local place, and it was cutting as good as new. I've gotten some more decent knives and a couple of good ones, since, and as I mention, I get them all professionally sharpened (costs me $5 each, although they have 3 "free sharpening days" every year, when I can get two knives sharpened, and I usually take advantage of it.
For my pocket knife, I use a sharpening stone and oil.