Elixir Strings are covered with an ultrathin, space-age polymer tube that contacts the string on the tops of the windings only. They're coated with the patented Nanoweb® technology. This leaves the all-important winding-to-winding-to-core space free from the enemies of tone! Most players report that Elixir Strings keep sounding great 3 to 5 times longer than ordinary strings.