Are you, or have you ever known anyone allergic to certain metals? I know there are quite a few people allergic to nickel out there. I know copper is another big one with people. I know I like the feeling on titanium on my skin. I have a titanium watch and a titanium handled pocket knife and I the metal just feels 'good' to me. It's strange. I know there are women that can't wear necklaces or earrings because of the types of metals they use and will break out in a rash. Anyone bothered by certain metals?