The Birchwood Aluminum Black Metal Finish is used by gunsmiths to blacken aluminum parts. It restores scratched and marred areas quickly. The fast-acting liquid is easy-to-apply with no dimensional change. The Birchwood Aluminum Black Metal Finish color will vary from deep gray to black depending on alloy. Aluminum Black is also excellent for blackening name plates, plaques, trophies and other engraved items.