Quite accidentally, I removed the matte finish partly on my Matrix-12. I had to clean off some of the foam from the road case which had adhered to the surface. I used denatured alcohol which removed the stuck on foam, but removed the matte finish as well. It did take a bit of "elbow grease" to get it all off however.
BTW: I was going to sell my Matrix-12 soon, but was worried about lost value because the finish had been removed. I am surprised some people prefer their instrument that way.