A little goes a long way. A lot goes even further. Introducing RED. The first brand of Copper Bronze acoustic guitar strings. With the highest copper content of any string material - more than 80/20 and more than phosphor bronze - RED Strings gives acoustic guitars precise articulation louder sound greater projection and a warmer richer tone from the moment you tune them up. There hasn't been a significant new material introduced for acoustic guitar in 35 years.