Wound to exact specifications, you can depend on these strings for tone, brightness and clarity on a daily basis. These 80/20 bronze strings deliver a superb bright sound. These strings are engineered with the performer in mind and they will always stand up to rigorous practice and performance schedules. Martin & Co. start with their highest tensile-strength core wire, then tin-plate it on all six strings for added corrosion resistance; because what you don't see matters! When coupled with their highest quality wrap wire, you get consistent true tone that you can count on song after song. 

This alloy is comprised of 80% copper and 20% zinc. It is popular for acoustic strings and provides a very brilliant tone when they are initially put on the guitar and mellow over time. High carbon steel with tinplating is used for the core wire of wrapped strings and the plain round treble strings