Shakudo, 95% copper 5% gold will self patinate on the hand but it
will also continue to dissolve due to electrolysis so it is not
really a solution for the long term.
That is a bit disappointing.
I suppose it’s okay for things that don’t come into contact with
skin or water, like a tsuba or a pot.
Wonder is a sacrificial anode would do the trick? Just a small piece
of metal that could be replaced when it wears out.
Regards Charles A.