At C.F. Martin & Co., they design their strings like they design their guitars — with maximum performance, exacting tone, and playability in mind. They know that musicians demand strings that will perform onstage, in the studio, or wherever their music takes them. Martin strings are designed to deliver excellent tone, clarity, and response and are made from the highest-quality materials. Treated with Martin's proprietary formula, SP Lifespan strings repel dirt and oil and play like new long after conventional strings wear out. Sweetwater knows that you take your choice in strings very seriously, so make the most out of your next restringing and choose Martin acoustic guitar strings.