Cleartone 7613 80/20 Bronze Acoustic String Set, Medium Only One micron of coating, but it's more durable than coatings thousands of times its thickness. It won't flake off with hard playing, nor will it feel slick or slippery to your touch. Super-high tension winding over a hex-core is used to maintain tuning consistency. EMP treatment is applied to ensure longest tonal life without compromises.