Designed to deliver unparalleled tone and playability, Martin Era™ strings set a new standard for phosphor bronze acoustic guitar strings. Incorporating the best technologies in the Martin range, Martin Era strings feature the patented Lifespan® coating for protection against corrosion, a Flexible Core for enhanced suppleness and playing comfort, and silk-wrapped ball ends—a premium touch designed for vintage instruments that recalls Martin’s long-standing artisanal tradition in string making. The “Artist Light” version was developed in collaboration with six-time GRAMMY® Award-winning artist Jason Isbell; it uses a more traditional SP® core, perfectly suited to the tonal signature of his guitar.