XT Coated Strings


First there was XL, then EXP, then NYXL and now, X—D’Addario’s most technologically advanced string ever created, for electric, acoustic, classical, bass, and folk instruments.
Our Research & Development team has been working to distill all of D’Addario’s uncompromising innovations like NY Steel and Fusion Twists into strings that finally put an end to the tradeoff between corrosion fighting coatings and natural tone and feel.

XT, the first series in the portfolio, combines high carbon steel core wire and plain steel strings with an extended lifespan treatment on every string in the set, resulting in enhanced break resistance, pitch stability, and long-lasting performance, all while preserving the tone and feel of your favorite uncoated strings.

These strings are made to stay, for performance that never fades away.

D'Addario XT Coating

This is a highly anticipated string, from our point of view, and something D'Addario has worked on for a long time. Their approach to coated strings has always been different to Elixir with the focus on creating a high grade of string which improves tone, strength, stability and longevity.

D'Addario have developed a process by which they treat the wrap wired and core of the strings with a newly developed, hydrophobic nano coating before it is made in to the string. Crucially, the Core of the string is treated which repels moisture from the entire string.

Microscopy Photo By Plymouth University for Soundunlimited ©

D'Addario NYNW050 for reference of closeup string structure.

As the string is made in the same way as an uncoated string, it is able to oscillate in the same manor and retain almost all of the tonal characteristics. If you think about the physics of how a string moves it is actually a wave moving up and down the string where the wrap wire behaves a bit like a spring. The micro flexing of the wrap wire is unaffected by the coating on XT Strings which is not the case with Elixir's method of complete coating.

This YouTube video by nicogetz is a great example of this. You can see just how much the string moves in order to generate the wave form of the pitch. Notice how the higher pitch notes have much shorter wave lengths. This visual is actually as a result of way a phone camera CMOS sensor works but the depiction is beautiful.

Example of a Hydrophobic material repelling a water droplet.

Hydrophobic Coating

This just sounds like word for Marketing but it is useful to fully understand the significance of this. Hydrophobic literally means "the fear of water" but in chemistry terms, hydrophobicity is the physical property of a molecule that is seemingly repelled from a mass of water.

The New XT Strings nano coating will repel moisture from the surfaces of all of the strings.


Elixir Coating

As one of the most well known coated strings, it is important to understand a little more about Elixir. Elixir were established in 1995 launching the first packs of Polyweb Coated Strings. They established a line of strings that lasted significantly longer by fully jacketing the string in their GORE-TEX® Polyweb coating. The brand has grown considerably with guitarists forming a love/hate relationship with the strings. The sacrifice of Tone for Longevity.

It has been recognised, by fully coating a string it fundamentally changes the way it feels and the way the string oscillates and therefore sounds. Elixir have utilised descriptive terms in their marketing to convey this. Such as, Polyweb sound 'Played In, Warm, Slick & Fast' while the thinner Nanoweb is 'Bright and Smooth', "closer  to the sound of an uncoated string". There is an obvious correlation with the tone of a string and the thickness of the coating. Elixir have more recently brought out their thinnest Optiweb Coating which they say is 'Crisp and Natural'.

Elixir also state that coating the whole string across the wraps stops sweat and dirt going in to the gaps between the string winding. This may well be the case but it is the major reason the string can never behave and sound quite like an uncoated string. We also find it is noticeable, as the strings ages and starts to tatter, intonation becomes a problem.

Will The Range Increase?

D'Addario launch the XT String with a wide range of types and gauges. As they have done previously with NYXL, they will likely expand the range over the next couple of years to include the more specialist string gauges such as Balanced Tension, 7/8 String, Drop Tuning and Singles.

Main product features are:


- Microscopic hydrophobic coating that protects all six strings in the set

- Coating protects the tone and feel of fresh strings. Strings last at least 3 times longer than uncoated strings

- Made with the high carbon NY steel coupled with fusion twist ball end fastening to deliver enhanced break resistance and tuning stability

- Research shows XT strings are up to 42% stronger and stay in tune 131% better than traditional strings

- Wire is drawn & coated, and strings are manufactured by D’Addario in our NY facility. Results in extreme quality control and consistency

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What is XT?

• XT is an extended lifespan treatment that we apply to every plain steel and wound string in the set. It features a proprietary

high carbon steel core and plain steel wire that significantly increases the durability and tuning stability of the strings.

Ultimately, XT delivers an extended lifespan string with

How does XT compare to EXP?

• XT features an improved coating that is thinner and more durable than EXP. The treatment is imperceptible, so it feels, sounds,

and plays like an uncoated string.

• The XT treatment is applied to every steel string in a set, unlike EXP which could only be applied to the wound strings.

Does XT treatment effect the tone of the strings

• We have proven that our XT lifespan treatment has little to no perceptible effect on the tone of the strings, compared to an

uncoated string. You wouldn’t know the strings were coated if we didn’t tell you.

How does it differ from NYXL?

• XT strings do not feature the proprietary Nickel Plated Steel wrap wire that NYXL uses, which gives NYXL its distinctive tone.