Made with an 80/20 bronze alloy wrap along with a layer of silk between the wrap and steel core. The silk produces a more mellow sound and makes the string feel more comfortable while reducing finger noise. Ernie Ball Earthwood Silk; Steel Soft 80/20 Bronze acoustic guitar strings are made with; 80/20 bronze alloy wrap along with; layer; silk between the wrap and steel core. The silk produces; more mellow sound and makes the string feel more comfortable while reducing finger noise. Gauges .011 .015 .022w .030 .042 .052