I recently owned a business that sells fancy display cases for knives. In the eight years I owned the company, I had many requests for wall mount display cases.
The more I thought about it, I realized there is no really
great way to display knives on a wall. I said really great because all the other solutions bother me.
Unless you have a French fitted case with strong glass in front, you have problems. And even that has problems.
Let me explain:
I clomp around the house like a bull moose, being a big guy and all. The thought of a jolt from my feet or worse, say an earthquake (or teenagers)

could bring down an ill attached knife is scary, if not dangerous. And that's the rub, so to speak. How to attach the knife or knives to a box or display conveniently and without interfering with your ability to view or handle the knife.
Take Velcro. Please. You could attach some to a box and your knife but yuck! Or stretch keeper straps; nice to see those black keepers on your $2000 knife. Or you could make a bunch of slots and merely stand them in there, but what about that jolt?
Plus, taking the box/display down and back up again begs for a crash eventually. That means glass shards and pointy objects everywhere, and you are standing in it. Or should I say bleeding in it.
Here's one idea I did not explore, memory foam covered in felt (or my personal fave, Ultrasuede®), with rare earth magnets behind it. I'm not sure how well it would work, but it's a thought. I have one knife that's held in it's sheath with rare earth magnets and they are very very strong. It might work.
It's a delicate task to wall mount and really not worth the effort, unless you permanently mount it/them in the style I first described. Not worth it unless it's, say, a ceremonial sword mounted above your fireplace with two custom made hooks lined with felt to prevent scratching. I do have one of those and it works pretty well. But I never take it down and I don't let teenagers in my house anymore...
