12-16-24W-36-46-56 43 inches 80/20 Bronze wound strings are often called old-school, vintage and/or bright bronze and were the most popular (only) alloy used to make acoustic strings until the introduction of phosphor in the early Seventies. 80/20 bronze wire is made from 80 percent copper and 20 percent zinc. 80/20 bronze provides balanced highs and lows with a slight increased in mid-range that seems to make the notes cut-through a little more. It took several years of trial and error to develop a proprietary string coating that resists tarnish and corrosion without compromising tonal quality.
I just put a set of 12-56 80/20 BRONZE BLUEGRASS SET COATED strings on my acoustic electric and I found my new favorite acoustic guitar strings. Amazing tone and feel. They feel like they are lighter Guage than they are. I highly recommend Curt Mangan strings they are truly the best strings I've ever played.