Hi, first of all thanks you a lot for your strings in general, because there the only i use since i started to play guitar few years ago and i love them, especially the flat wound and the half round, BUT this time unfortunatly the g and b strings was definitly not in the best shape when i open this set of half round (some kind of black crust here and there, impossible to remove) it's the first time it happens, bad luck for me, i gonna do with it. I consider putting heavy gauge next time, and set my guitar differently. See if i can lower the action, and set my neck straight. Thanks you again. Sometime i imagine a world where we cannot produce steel string anymore and it make me quite inconfortable :p