It survived attacks from my #11 craft blades mostly. The one where I slipped out of my material and hit it hard left a mark. Otherwise the only way I hurt this was using a compass on it. It's rather hard so I had to stab it pretty hard. This left a tiny hole. Any other mark from the knife sealed well with some rubbing.
Do not trust the ruler. I checked it against a different ruler for a couple of inches. Somewhere it changes.
But for what I do, I need to protect my table and this works well for that.