Optima Acoustic Gold, .013 - .057, AG1747Mstar rating 5Russell TJanuary 24, 2010I have tried just about every string out there on my Collings D2H Baaa dreadnought. Nothing drives it better than this string. It has the most natural full rich sound. These strings last longer than any string i have used,so i don't think they cost anymore and i change strings frequently. I am done searching this is by far the best string for me to play on any fine acoustic guitar.