Dragon Skin Acoustic Guitar Strings feature DR's K3 Clear coating on a phosphor bronze wrap wire to prevent dirt and perspiration from reaching the hexagonal core wire, preventing corrosion. The K3 coating, which is applied to all strings in the set, is ultra-hard and doesn't dampen vibration like softer coatings do. The strings have more projection, fewer unwanted overtones, greater clarity and articulation than uncoated strings.