Product Description BLACK BEAUTIES Black Colored Acoustic Guitar Strings aren’t just about the sleek and sophisticated look. They feature a hexagonal core wire and a phosphor bronze wrap wire to maintain brightness and feel. All strings in the set are coated with a jet-black version of DR’s K3 ultra-hard coating delivering longevity more projection fewer unwanted overtones and outstanding clarity and articulation. From the Manufacturer BLACK BEAUTIES™ Black Colored Acoustic Guitar Strings aren’t just about the sleek and sophisticated look. They feature a hexagonal core wire and a phosphor bronze wrap wire to maintain brightness and feel. All strings in the set are coated with a jet-black version of DR’s K3™ ultra-hard coating delivering longevity more projection fewer unwanted overtones and outstanding clarity and articulation.