Thomastik-Infeld Plectrum Acoustic Guitar Strings are soft sounding and have low tension on the bottom end. The plain strings are made of brass coated steel. The wound strings have a silk inlay combined with a highly flexible steel core. A, D, and G strings are polished bronze flatwound, while the low E is polished bronze roundwound. Gauges: .012 - .015 - .024 - .033 - .044 - .059.