Martin 80/20 Bronze .011 - .052 Custom Light Acoustic Guitar Strings Martin Stringsare theacoustic stringof choice for musicians around the world. Wound to exacting specifications, you can depend on these strings for tone, brightness and clarity on a daily basis. These80/20 bronze stringsdeliver a superb bright sound. 80/20 Bronze This alloy is comprised of80% copper and 20% zinc. It is popular foracoustic stringsand provides a verybrilliant tonewhen they are initially put on the guitar and mellow over time.