D'Addario XL Electric Guitar strings are world-renowned as The Player's Choice amongst gutiar players of all genres and styles. XL strings are wound with nickel-plated steel, known for it's distinctive bright tone and excellent intonation.
D'Addario String Alloy/Tone Glossary
Electric and acoustic guitar strings, as well as all of their bass strings are produced by winding a wrap wire around a high-carbon steel hexcore wire. The type of alloy used as the wrap wire determines the tonal quality of the strings. Here's a quick reference guide: