Unique 28+ Martin M140 80/20 Acoustic Guitar Strings, Ligh...
Unique 28+ Martin M140 80/20 Acoustic Guitar Strings, Ligh.... Martin traditional strings are our flagship line that stands the test of time. Site1prod100021 100021 martin m140 80/20 bronze light acoustic guitar strings skip to main content skip to footer. Martin traditional 80/20 bronze acoustic guitar strings are made with bronzed steel core wire and bronze wrap wire. The bronze winding alloy makes guitar strings have deep, rich basses and clear, bright trebles.