The Augustine Classic series strings have sweet trebles and rich warm basses. This series uses a nylon monofilament resin developed by Dupont, a beautiful sounding string, (but can be prone to inconsistencies in intonation in the trebles due to a softer formulation of nylon). These strings were the ones Segovia himself made famous. Models: Blue, Red, Black (S.P.), Gold (note that the "Gold" have Gold colored basses and all other models have silver basses).Classic_01 E/1st .029 clear nylon Classic_02 B/2nd .032 clear nylon Classic_03 G/3rd .040 clear nylon Blue_04 D/4th .031 silverplated copper wound Blue_05 A/5th .0375 silverplated copper wound Blue_06 E/6th .0445 silverplated copper wound