I can't be using up laser time to mark my products with engraved logos, especially inside curves of brass bracelets, so I thought of making a universal stamp that I could use to mark all my products quickly, whether plastic or metal.

I was thinking of reverse engraving some 1/8" silicone sheet that I have, mounting on a hand stamp, and marking plastic by dipping the stamp pad into white or black lacquer thinned with methylene chloride (acrylic solvent cement), but I want to use the same stamp for marking brass. Any idea of what type of metal marking ink I can use? I was thinking of some kind of acid. The silicone is pretty impervious to solvents and acids.

I have acid etch cream (hydrochloric, I think) for my CAT II certified safety glass stamp. I think I will test it to see if it marks metal.