You can get Birchwood Caseys cold blue and apply that (it works better if the part is warmed in an oven but in most cases your "matte" finished are "applied finishes" you could go the duracoat route, but that's a lot of stuff for one little part.
I put CT grips on my SA Loaded Micro Compact. Because it has an ambi safety I had to modify the safety on the right side. I found a post on the CT forum on how to cut the safety lever. Sooooo, I got out my trusty Dremel and went to work. Didn't come out bad at all. Patience is the key.
Well I ended up with a bare silver metal end to the now nubbed safety. I purchased a Birchwood-Casey Super Black touchup pen. It did a not bad job, but I've already chipped the paint exposing a bit of shiny silver metal.
Is there a product I can get that will actully meld with the metal to make a permanent matte black finish?
Thanks. (I'll post pictures once it's done."