D’Addario Classic Guitar Strings (EJ29, EJ30 and EJ31) have rectified mono-filament nylon trebles. Rectified nylon strings are known for their “warmer” tone.
Each classic treble string is ground using proprietary grinding techniques to control roundness and dimension in order to give (what the maker claims to be) “absolutely perfect intonation”.
The bass strings are silver-plated copper wire wound on nylon.
They are available as full sets in Normal (EJ30), Hard (EJ31) AND “Moderate”/[mixed] (EJ29) tensions. They are also available as treble only half sets.
Classic Guitar Strings (EJ29, EJ30, EJ31), Diameter and Tension at pitch.
(647.7mm scale length used for tension measurements.)