ACOUSTIC GUITAR STRINGS BLUEGRASS: .012 .016 .025w .035 .045 .056 D’Addario’s new EXP Extended Play Coated Acoustic Guitar Strings are nothing less than amazing. They're coated, but they feel, look and sound like traditional acoustic guitar strings. So why play coated strings if they feel, look, and sound the same? Because they LAST LONGER! The coating keeps all the sweat, oils, acids, and other nasty grime out of the windings of your strings. The "new string tone" lasts three to four times longer than traditional guitar strings. The secret to D'Addario's success with EXP strings lies in the manufacturing. An ultra-fine layer of EXP coating is applied to the phosphor bronze wrap wire before the wire is wound around the high-carbon steel hex core. Because the wrap wire is coated first, and then wound onto the core wire, the string retains the feel and sound of a regular phosphor bronze string, sounding fresh and bright. And, to top it off, D'Addario coats the plain strings with a bronze plating to help ensure that the plain strings will last almost as long as the wounds. No wonder they're called, "The Player's Choice". DA-EXP19$12.37 String Coatings for Longer String Life