Blackened fingers from flats

[1977jazz]

My brother's plucking hand finger tips are blackened after playing. Good, high quality strings. I'm thinking a chemical situation between his fingers and metal. Personally, I've never experienced this.
Thoughts?

[joinercape]

This happens with new flats sometimes, it is generally just the polishing compound left from the maker. I usually clean new strings with alcohol before installing them anyway, just to avoid this sort of thing. But no big deal, clean them and play on!

[One Drop]

Probably Chromes? happened to me with two sets in the past. Best to wipe them down first.

[JustDavid]

+1

"Chromes" was my first thought on reading this.

[One Bad Monkey]

It's a chemical reaction between the strings and his fingers. I have this happen to me, regardless of string type or brand. I've found it's much more noticeable with older strings than newer ones, but it happens on all of them.

It "could" be the strings themselves too (my first set of Circle Ks had my fingers extremely black after playing every night), but that's more of an exception. I'd bank it on his fingers over everything else.

Best advice is to wash your hands before playing and wipe down the strings afterwards.