Thomastik-Infeld Plectrum Guitar Strings Review

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Written By Musical Scoop

Chief Music Officer

Back in 1919, two of Vienna’s finest acoustical engineers decided to combine their research efforts. Franz Thomastik and Otto Infield originally decided to keep their business enterprises separate, despite occupying the same building in Vienna.

Because they shared an address, the Vienna government registered the businesses as one enterprise, and in 1921, the companies officially combined.

It takes a lot to keep a guitar string company’s doors open for more than 100 years, but Thomastik-Infeld has a few tricks up its sleeve.

The company patented several key string innovations, including the usage of steel strings in plucked instruments (they were previously used strictly for pianos).

Furthermore, the company has done an admirable job of developing a culture around itself and fostering long-term customer relationships.

Because of this, Thomastik-Infeld currently positions itself as a premium producer of strings for all kinds of instruments, including the acoustic guitar.

The company offers several different versions of acoustic guitar strings, but this review focuses primarily on one of their more popular series, the Plectrum.


Seeing as Thomastik-Infeld spent the last hundred years refining their product, one would expect their Plectrum series acoustic guitar strings to sound phenomenal.

Fortunately, this assumption proves to be true, and these strings provide players with a richly warm and balanced sound.

One of the most redeeming attributes of the Plectrum series string line is the precise balance across the frequency spectrum.

This is especially evident in the high strings, which sound clear and crisp but do not punch through the sound nearly as much as many competitive strings.

If you like a shrill high end, these probably won’t suit your taste. This balance best suits acoustic singer-songwriters, jazz artists, and rhythm guitarists; lead players looking to solo and stand out from the mix would be better off investigating Thomastik-Infeld’s related product, the Spectrum series.

Basic Construction and Durability

Interestingly, the actual construction of the various strings in the Plectrum series varies considerably from most of Thomastik-Infeld’s competitors.

In order to achieve such a smooth balance throughout the range of the instrument, the company opted to use several different types of strings.

The lowest E string is roundwound, while the next three strings feature a flat wound design. The two top strings consist solely of steel wires.

Furthermore, all of the strings utilize a silk inlay. The addition of the silk serves primarily to control the harmonic and overtone characteristics of the string, though they do also change the overall feel and tension of the string.

Speaking of tension, that’s another area that the Plectrum series that differs substantially from other strings. Thomastik-Infeld designed these strings for low tensions.

This not only noticeably warms up the tone, but also makes these strings suitable for use on vintage equipment not designed to handle today’s high tension strings.

When Thomastik-Infeld chose to alter the construction of their Plectrum series in the ways previously described, there’s little doubt the company focused primarily on warming the sound.

However, these modifications also increase the life of the string, granting the Plectrum series supreme durability.


The one downside to using low-tension strings is tuning issues.

Unless the manufacturer specifically calls for low tension strings, the construction of the neck, fretboard, and tuning pegs was likely designed to hold high tension strings in tune.

Without proper stretching and care, low tension strings often take longer to lock in tune.

While Thomastik-Infeld’s Plectrum series is no more susceptible to this than their competitors, players ought to recognize the potential for tuning issues when using low tension strings on an instrument designed for higher tensions.

This can be remedied by adjusting your truss rod in your neck, however, before you start playing with your truss rod make absolutely certain you know what you are doing or you risk damaging your guitar.

Price and Availability

Unfortunately, many physical stores fail to carry Thomastik-Infeld products, especially outside of Europe but that’s the nature of boutique guitar strings.

That being said, one shouldn’t find it too challenging to locate these products online.

Both dedicated online music equipment retailers and more general marketplaces carry these strings in a variety of gauges.

Expect to pay in the neighborhood of $15-20 per pack, but well worth it if you want an extremely well-thought-out string set.

Though these strings cost more than many of their competitors, the unique sound, durability, and low tension differentiate the product enough to justify the uptick in price.

All in all, the Plectrum series strings are a great value from a company that really knows its stuff. You can’t go wrong.