The first year I sold knives made by the BUSSE Combat Knife Co., I had to re-evaluate how I define 'shaving sharp'.
A small portion of the knives I received were not what I would refer to as shaving sharp.
Another small portion were not only shaving sharp, but using a push cut, would not differentiate between hair and arm, and in fact were only safe to shave with if suspended above the skin where they could safely cut through the hair without actually coming into contact with my skin.
I have seen many people pick a knife up off of the show table and shave with it before I could stop them.
Some of them would use a slight slicing action because, I suppose, the knives that they were used to would not push cut and shave hair.
Some of these people I simply directed to see their personal physician, and some I suggested should go directly to the emergency room while applying direct pressure.
It was Jerry who taught me to either use just the back of my nail, or to cut through (once again in a push cut) the skin from a callous as opposed to shaving in order to determine knife sharpness.
Alas, I was not always smart enough. I have a fine line on my arm neither quite so deep, or quite so wide as the one in the above picture, relating to my doing what Jerry told me, which was stop the customer from shaving his arm, and if the customer absolutely insists on a shaving test, to do it to myself.
Some of these knives are amazingly sharp.