Ernie Ball Earthwood Silk & Steel Soft 80/20 Bronze acoustic guitar strings are 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. Gauges .009 .009, .012 .012, .020w .009, .026 .012, .036 .020p, .046 .026