STRING SET FOR ACOUSTIC GUITAR String set for Addario acoustic guitar EJ silver wound Silk &, Steel. Soft sound ideal for small body guitars. Calibers (011 - 014 - 023 - 028 - 038 - 047). The Silk &, Steel strings are made with a pair of copper-plated wires and silk covers rolled together for easier fingering and a soft tone. They are excellent for acoustic guitars with the smallest body and preferred by many Folk guitarists.