[HELP] Suggestions for writing on harmonica metal plates

[Highpower]

That is a good idea as well from Vinny. It has the extra benefit of being able to scale the signature to fit whatever size harmonica you want to put it on. These folks are in St. Louis, and do excellent work at reasonable prices. I had them do some 2D pantograph engraving for me in the past and was very pleased with their work.

[PixMan]

If you want the original hand signature on the metal, you can use a sharp solid carbide scriber that will scratch the softer metals easily. It will never be deep, and even then you have to tell the artist to "press HARD". Not being deep the signature would be subject to wear so would have to be protected.