I bought these as it's difficult to find coated strings for mandolins. My fingers can tarnish a set of strings in a single session, so I wanted something that would last a little longer. I've had these on for a couple of months and they're.... OK. Not perfect, they have tarnished a little, with only quite light usage. I'll buy them again as they're better than some of the other strings I've tried, just not as good as coated strings (Elixir etc.). They do look very nice on the instrument though, and they sound good and seem to be good quality.