What is that rainbowy finish used on antique guns?

[bronzeo]

Looks like heat applied to chemical of course. If applied right, it is really cool. Being a founder, I have a lot of chems used in patina of bronze.

Also what is the stain or patina used to antique the cut and backgounds on stainless engravings? Thanks, Jack

[Dave London]

Jack
I believe that you are refering to color case harding, thier are several different methods to do this I would check google for more info:cheers2:

[NevadaBlue]

Yes, as Dave said, color case hardening. It is a difficult and tedious thing, not a finish really. It is made by heating the metal in a special atmosphere with carbon in contact with the surface and then by dunking it into a bath of bubbling water typically. The reason for it is to apply a hard outer layer for wear protection, the beautiful colors are a secondary thing.