Ernie Ball have long been renowned as the world’s most popular guitar string manufacturer. However they do tend to write rather opaque product descriptions! I have included their description of these strings below, but here is a brief synopsis from me. There are two main materials used for winding acoustic guitar strings- 80/20 bronze and phosphor bronze. Phosphor Bronze has a brighter, clearer sound but tends to rust a little faster, and 80/20 bronze is more mellow but maintains the same tone a little longer.
As 12-string guitars are very bright sounding anyway, thanks to their double course strings, I much prefer the 80/20 sound and longevity for 12-string guitars. Personally these are my favourite 12-string acoustic guitar strings, despite the advice of one music shop owner who told me many years ago that Earthwood 80/20s had a “languid tone”!
Here’s what Ernie Ball have to say:
Made in the USA Ernie Ball 80/20 Bronze Alloy Earthwood acoustic guitar strings range give a full bright sound. Made from 80% copper, 20% zinc wire wrapped around hex shaped tin plated steel core wire. The most popular acoustic guitar strings provide a crisp, ringing sound with pleasing overtones.