Elixir Nanoweb Acoustic Guitar strings are coated in a unique way to protect wound strings from all contaminants. A flexible, strong, yet micro-thin polymer tube defends the critical zone of tone from invading enemies. Nothing ( including the coating ) gets between the windings. Elixir strings with the original Nanoweb coating apllied sound great 3 to 5 times longer than ordinary strings, have the bright tone & punch of non-coated strings & feel like traditional strings. After experiencing Elixir guitar strings, it's hard to go back to the old way of life.