While cleaning up, I recently found a box (still had 6 packs in it) of shrink-wrapped strings for my electric guitar: D'Addario EXL120 Nickel Wound 9-42. I guess they have been sitting around in my storage room for about 12 years, still shrink-wrapped.
I put on one of the sets on my Telecaster last week, and found that the strings don't sound or feel fresh, at least not like I remember from having used this brand several years ago. Even after only 2 hours of play over the last couple of days, they sound and feel like they have been on there for several weeks. Compared to my other guitars with new strings, they sound dull.
Does the strings' quality deteriorate even though they're shrink-wrapped? How long can I store strings before they lose their freshness out of the box?
Have other people seen the same issue with strings that have been sitting around for a long time (several years)?