The EXP series has a micro-fine layer of EXP Coating bonded to the Phosphor Bronze wrap wire, before winding over the hex core wire. This creates a built-in barrier against contaminants and corrosion that can shorten the life of your strings and make them sound dull. EXP17's have a natural round wound feel and extra-bright tone that lasts up to three times longer than normal strings. In addition, the plain strings are Compound Plated for extra endurance and long life. Together, the coated and plated strings will give you much more life out of your acoustic strings. The EXP series goes an extra step beyond the basic Phosphor Bronze strings, which D'Addario introduced their Phosphor Bronze strings back in 1974, and they kept their warmth and tone.
