Ernie Ball Ernesto Palla concert quality classical guitar strings are made of a solid nylon filament Gold fourth, fifth, and sixth wound strings are made of 80/20 bronze plated copper wrapped around a nylon floss core providing a smooth, rich tone. All Ernie Ball guitar strings are precision manufactured to the highest standards and most exacting specs to assure consistency, optimum performance, and long life. Gauges First .028, Second .032, Third .040, Fourth .030, Fifth .036, Sixth .042 Medium tension