D'Addario's heaviest 80/20 Bronze gauge, EJ12s offer heavier tension resulting in a bolder, more resonant acoustic tone with higher resistance for heavy strumming and flat-picking. 80/20 Bronze, commonly referred to as brass, is the original acoustic string alloy selected by John D'Addario Sr. and John D'Angelico in the 1930s. 80/20 Bronze strings are popular for recording due to their crisp, deep and projecting tone and appeal to many traditionalists and vintage enthusiasts for their historical significance. All D'Addario acoustic strings are wound on a hexagonally shaped, high carbon steel core, resulting in long lasting, bright sounding tone with excellent intonation. D’Addario 80/20 Bronze acoustic guitar strings are precision wound over a hexagonal high carbon steel core. The 80/20 Bronze wrap wire provides bold, bright acoustic sound, with crisp projection that fills the room. 80/20 Bronze was originally created by John D’Addario Sr. and renowned guitar maker John D’Angelico in the 1930s. Our 80/20 Bronze acoustic guitar strings come with a code on the recyclable VCI bag, which you can register to earn Players Circle points. D’Addario 80/20 Bronze strings are made in the USA—drawn to our exacting specifications at our New York production facility.