Many players find their strings losing brilliance after just one gig. Deposits of sweat, grease and dirt are particularly hard to remove from wound strings, and quickly affect the sound and playability of even the best guitars, resulting in a dull tone and greater friction with the fingers. Wiping the strings immediately after playing can help, but lately, a more high-tech solution has been developed by the manufacturers of Gore-Tex waterproofing. Elixir strings employ a thin plastic coating which is designed to seal the string without affecting the sound. Elixirs original Polyweb coating has recently been joined by the even thinner Nanoweb coating.
Meanwhile D’Addario offers a great alternative in the coated string area with its X-Series – which includes XS and XT.
XS uses a really thin (1/10 of a human hair) film coating, that wraps completely around the strings and protects the spaces between the windings from sweat and build up. The material greatly extends the lifetime of the string, reduces finger noise and gives a smooth feel while maintaining the familiar D’Addario string sound.
XS strings are a good choice for guitarists, that are looking for maximum lifetime and a smooth playing feel.
XT strings on the other hand are meant for guitarists, that want to keep the traditional playing feel of an uncoated string with extended lifespan.
To maintain the uncoated feel of the string XT strings use a microscopically thin (1/30 of a human hair) dispersion treatment, which is applied to the wrap wire first before it gets wrapped around the core. This technology keeps the traditional winding structure untouched, so you won’t be able to tell any difference in sound or feel compared to an uncoated string. At the same time the treatment greatly expands the life of the string. A similar technology was used for the older EXP strings, that now are discontinued because of the highly improved properties of XT.
In XS and XT sets also the plain steel strings are coated, so you get protection of the complete string set, not just the wound strings.
Another unusual process is employed in the manufacture of Dean Markleys Blue Steel strings - rapid freezing in liquid nitrogen followed by a gradual return to normal temperature. It is claimed that this results in longer-lasting brilliance.