Phosphor bronze sets are available in seven different sets from extra light to medium, plus one set in bluegrass gauging and another for slack key. The plain steel strings are silvered. Players have reported that they are amazed by the intonation and life of these strings. They like the tone crispness and projection that these strings produce. Great for finger picking. We carry not only the phosphor bronze but silk and steel and for both 6 and 12 string guitars as well as other instruments.