Guitar Strings from the 18th Century to the Advent of Nylon (Part 4)

Types, Manufacturing Techniques, and Selection Criteria

by Mimmo Peruffo

The foundations that shaped the 20th-century guitar were laid as early as the second half of the 19th century, primarily through the advent of Antonio de Torres’s guitar. Nevertheless, no one at the time could remotely foresee the epochal transformation that synthetic chemistry would bring to the guitar world by the mid-20th century. We will not, of course, delve into the organological and constructional details of our instrument, which can be found in more recent works.¹⁰⁹ What matters here is that with Torres, the vibrating length of the guitar increased and stabilized at around 65 cm, a standard that has largely persisted to the present day, with a few exceptions, such as the instruments crafted by the Ramírez family (with a vibrating length of approximately 67 cm). The reasons that prompted this great luthier to adopt this specific increase remain unknown, especially since string technology and pitch standards did not undergo any noteworthy changes from the prevailing norms.
Regarding the pitch standard of the late 19th and early 20th centuries, it can indeed be argued that it stabilized at approximately 435 Hz, a result of the first effective international agreements at the turn of the century.

The 20th Century

As for string production, it is regrettably necessary to note the onset of an irreversible phenomenon: the abrupt collapse of Italy’s glorious, centuries-old tradition, which had been a cornerstone of European musical craftsmanship for ages.¹¹⁰
While in Italy string production—widespread across much of the central-northern region—was consistently characterized by an exclusively artisanal and individualistic approach, in France, string makers enjoyed the attention of the state administration, which regarded them with pride. In Germany, the production of gut strings had effectively taken on an industrial character. Although the quality of German products often left much to be desired (these were inexpensive but rather rigid strings),¹¹¹ by the early decades of the 20th century, German manufacturers were able to dominate a significant portion of the European market. This dominance persisted despite the rapid and growing adoption of metal strings among bowed instruments—the primary users of harmonic strings.
The reasons for Italy’s swift decline, beyond the “fragmented” nature of its national production, likely lie in the broader economic hardships that burdened the population at the time. These difficulties stemmed partly from the still-recent unification of Italy in the initial phase and later from the events of the 1915–1918 war. To make ends meet, many Italians chose emigration, including several string makers. Some of these individuals, despite immense challenges, laid the groundwork for what would later become the thriving North American production (e.g., D’Addario, La Bella-Mari, etc.—all surnames of Abruzzese origin).
It remains unclear when the guitar began to diverge from its reliance on violin string comparisons. We might hypothesize that this shift coincided with the increase in its vibrating length. Such a “detachment” became necessary to maintain working tension values more or less consistent with established practice, as a longer string length requires the use of thinner gauges. Indeed, transitioning from a vibrating length of approximately 62 cm (typical of guitars from the first half of the 19th century) to 65 cm—nearly a semitone longer—would result in an increase in working tension of almost 1 kg in total if the same strings were used.
To obtain meaningful data specific to the guitar, however, we must turn to Pujol.¹¹² Based on the precise indications provided in his Method, it becomes clear that there was indeed a slight reduction in the average diameter of treble strings compared to the previous century. More significantly, for the first time, a certain graduation in working tension appears—an aspect virtually unknown in 19th-century guitar string setups:
Diameters in tenths of a millimeter.*
First: from 12.5 to 13.5 (0.63–0.68 mm)

Second: from 16 to 17.5 (0.80–0.88 mm)

Third: from 20 to 21.5 (1.00–1.08 mm)

Fourth: from 15 to 16 (0.75–0.80 mm external)

Fifth: from 18.5 to 19.5 (0.93–0.98 mm external)

Sixth: from 23 to 24 (1.15–1.20 mm external)

At a pitch standard of 435 Hz and a vibrating length of 65 cm (Pujol owned a Torres guitar), the following ranges of working tension values emerge:**
E: 7.4–8.6 kg

B: 6.0–8.1 kg

G: 6.6–7.7 kg

Although these are gauges specific to the guitar, the alignment of the three treble strings with those in use for the contemporary violin remains striking and persisted for at least another decade. Consider, for example, the violin diameters suggested by Carl Flesch in 1924:¹¹³
NOTE E DIAMETER 0.63 mm

NOTE A DIAMETER 0.82 mm

NOTE D DIAMETER 1.09 mm

Interestingly, Pujol suggests that the second string should be exactly half the thickness of the third and double that of the first, justifying this by stating that “the need for a certain clarity that supports the expressive character of the first string on this one leads to a preference for it being slightly thin, provided it does not lose pitch.” The meaning of this statement is not entirely clear to us: the table instead reveals that the diameter of the second string is precisely the average of the diameters of the first and third strings.
The Manual still includes the traditional test for distinguishing a false string from a good one, indicating that at the time, strings were still hand-polished. Noteworthy is the description of the Pirastro micrometer for measuring string diameters, a tool that was beginning to replace the old 19th-century plate gauge.
A direct consequence of introducing graduated tension was that the tactile sensation of stiffness began to manifest more uniformly across the strings.
Here are examples of gut violin strings we have recovered, dating to the early decades of the 20th century, which provide a useful comparison with those of the guitar:
NOTE DIAMETER OBSERVATIONS

1st E 0.66 mm Oiled paper envelope ‘Bimba,’ London. High twist.

1st E 0.68 mm Unidentifiable envelope. High twist.

3rd D 1.14 mm Unknown provenance. High twist.

3rd D 1.17 mm ‘Lustral’ envelope, Valtelot-Hekking, Paris. High twist.

Next, here are measurements of gut guitar strings, possibly from the 1940s or 1950s, found intact in their sealed packaging. They are marked with (a) for strings kindly provided by luthier Lorenzo Frignani of Modena and (b) for samples found in the case of a Torres guitar from 1867, housed at the Palacio de la Guitarra in Ibaraki, Japan:
NOTE DIAMETER OBSERVATIONS

E 0.64 mm Oiled paper envelope ‘Perfect,’ France. Medium twist. (a)

E 0.65–0.67 mm Unused coiled string. High twist. (b)

A 0.84–0.86 mm Unused coiled string. High twist. (b)

G 1.02–1.04 mm Unused coiled string. High twist. (b)

G 1.0–1.03 mm Unused coiled string. High twist. (b)

G 1.02 mm Oiled paper envelope ‘Perfect,’ France. Low twist. (a)

G 1.05 mm Oiled paper envelope ‘Celesta,’ France. Low twist. (a)

These measurements show complete alignment with Pujol’s data, further confirming the graduated working tensions and the lingering—albeit unacknowledged—connection with violin gauges. In other words, the violin is no longer explicitly cited as a reference point.
It is worth noting the limited elasticity observed in some of the above samples: hard and rigid to the touch, they are made with a low degree of twist, a characteristic that markedly distinguishes them from the high-quality strings produced in 19th-century Italy and France. It should be recalled that a poorly twisted string, due to its significant rigidity, hardly delivers optimal acoustic performance.¹¹⁴
It must be pointed out that the average working tension of the chanterelle did not actually vary from the 19th century if one considers that the increase of approximately one fret in vibrating length, introduced by the Spanish luthiers, corresponds to a compensatory reduction in string diameter equivalent to about one semitone.
Let us now examine some samples of silk-wound strings, likely from the 1930s or 1940s, to compare with modern ones, particularly regarding the diameter of the metal wire used, the external diameter, and the equivalent gut gauge. As previously noted, strings marked (a) and (b) come respectively from luthier Frignani and the Torres guitar at the Palacio de la Guitarra, while the one marked (c) was provided by Kenneth Sparr of Stockholm.

The Advent of Nylon

With the emergence of polyamides (nylon)—on the eve of World War II—the landscape changed radically. It may not be widely known that Andrés Segovia played an absolutely pivotal role in driving the application of new synthetic materials as substitutes for gut during a historical period when, due to the war, all available gut was requisitioned for military surgical thread.¹¹⁵ In Italy, for instance, the Allies reportedly “seized” the last remaining gut string production centers—such as Salle and Musellaro in Abruzzo—redirecting them to the massive, exclusive, and “Top Secret” production of suture thread. This new production focus has persisted to this day, almost entirely supplanting the manufacture of harmonic strings.
In this context, where finding gut strings for musical use was an impossible feat, polyamides suddenly entered the scene. The gold medal for technical experimentation applied to the guitar unquestionably belongs to Albert Augustine, a New York luthier known to Segovia. Under the Maestro’s relentless pressure, Augustine succeeded in refining this newly discovered synthetic filament (1938), developed by Dr. Wallace Carothers, head researcher at the DuPont Company’s laboratories, for musical purposes.¹¹⁶ This new class of materials, boasting extraordinary mechanical properties, was christened by the company with the generic “surname” nylon. Perlon (polyamide 6), the progenitor of the nylon series, was immediately employed for fishing lines, women’s stockings, and, above all, military parachutes.
Already by early 1947, Segovia was among the first to test nylon, thanks to filament samples (not yet fully fledged strings) provided by General Lindenman, a key figure he met by chance during a reception at the Spanish Embassy in Washington on Christmas 1946. During the event, Segovia casually complained to him about the chronic shortage of gut strings—particularly chanterelles—due to the war (recall that Germany held the lead in European production in the 1930s). The general promised to send him samples of the new material, which he would confidentially request from DuPont. A month later, nylon filaments resembling a guitar chanterelle arrived at Segovia’s hotel. He tested them immediately on his instrument, instantly recognizing their immense potential. From that precise moment, the era of gut came to an end forever. Despite skepticism from DuPont’s own experts, Albert Augustine—apparently in collaboration with the Mari/La Bella firm, renowned New York string makers of Italian origin specializing in gut strings—¹¹⁷ succeeded, under Segovia’s constant encouragement, in finalizing the treble strings and developing basses with a new nylon flock core: a kind of “artificial silk,” in essence.
This enabled the first commercial production of synthetic guitar strings under the “Augustine” brand. DuPont promptly developed—by the early 1950s—products better suited to music (i.e., with a high elastic modulus and low moisture absorption), such as polyamide 6-12 (better known as Tynex, still used today for guitar strings). However, its primary use, then as now, centered on producing synthetic bristles for… toothbrushes.¹¹⁸
One might wonder whether the transition from gut to nylon entailed significant changes in gauge selection and working tensions. The answer is yes, but with important qualifications.
The first consideration concerns the acoustic and mechanical properties of nylon in the treble strings. Without delving too deeply into technical details, which have already been extensively covered,¹¹⁹ it should be noted that this material offers low atmospheric moisture absorption (approximately 3% at saturation for Tynex, compared to about 20% for gut), low cost, a perfectly smooth surface—unachievable with gut—and remarkable abrasion resistance. These are undeniable mechanical and reliability advantages, but they do not inherently affect sound quality. On the downside, the specific gravity of polyamides is moderately lower than that of natural material (1.07 g/cm³ versus 1.30 g/cm³ for gut), a significant handicap from a sonic perspective. This translates into a less brilliant acoustic output, with a less crisp attack transient and more noise compared to gut, which in some ways resembles carbon more closely than nylon. In other words, the advent of nylon marked the first notable departure from the acoustic tradition induced by gut strings since time immemorial.
In the bass strings, however, a true revolution occurred. Nylon in multifilament form boasts such superior tensile strength compared to silk (along with lower moisture absorption) that it allowed, for the first time, a significant reduction in the core diameter in favor of the metal wire. The result was a substantial enhancement in the acoustic performance of the bass registers, virtually unknown to guitarists until then. For example, in the low E string, the silver-plated copper wire increased from a mere 0.30 mm, typical of silk-core strings, to the current 0.35 mm, greatly benefiting the sound. Put differently (since sound quality—at the same equivalent gut gauge—depends on how thin the core is), in the early 20th century, the silk core diameter of the low E was around 0.70 mm, whereas with nylon, it dropped to approximately 0.52 mm. In both cases, a bass string is designed to operate near its limit, typically one or two semitones below the core’s breaking point. The approach of this exitus becomes evident as the string ceases to increase in frequency despite turning the tuning peg, while small crackling sounds emerge from the fibers breaking rapidly within the string itself.
It should be noted that the new bass strings exhibit greater longitudinal stretch than those with silk cores, requiring more turns of the tuning peg to reach the desired pitch—a benefit for tuning precision.
For the treble strings, the vocal quality of gut was thus traded for the low cost, reliability, climatic stability, and tuning consistency of nylon. However, the acoustic output of the trebles became more muted and less brilliant (an issue only partially addressed by carbon, a Japanese-patented material introduced in Europe in the 1970s, with a specific gravity far exceeding that of gut: 1.78 g/cm³ versus 1.30 g/cm³), yielding a sound that is certainly prompt and incisive but often deemed “emotionally cold” by many.
The emergence of synthetic materials inevitably led to a certain technological leveling. While gut strings were artisanally produced by numerous European manufacturing centers, each following its own concept of a string, polyamide filaments are now manufactured by a handful of international producers. Most companies that “produce” guitar strings ultimately limit themselves to packaging after purchasing “rods” weighing a few kilograms, consisting of thousands of nylon filaments of the same size—filaments that, in truth, can be used for various purposes, including musical ones. The available commercial gauge ranges have long been standardized—read imposed—by the company extruding the filament. The same situation applies to bass multifilament, sold in standardized sizes based on criteria derived from the textile industry (since it is primarily used as a reinforcement component in car tires and general textile applications). In the end, it is merely a matter of wrapping it with silver-plated copper wire or other alloys—such as brass or, more rarely, alloys with higher silver content—and cutting the resulting string to commercial length.
It follows that strings produced by various brands are inevitably quite similar—if not identical—to one another. This is hardly surprising, given that the nylon multifilament is virtually always the same for everyone, and the metal-to-multifilament ratio has long reached an optimization point beyond which the string under tension might break prematurely. The same issue applies to nylon treble strings, which also follow predetermined industrial production channels. This can be readily verified in the following table, which compares guitar string sets from some of the most well-known brands.¹²⁰
Hannabach Series 815 Low Tension, green envelope:
NOTE Ø STRING Ø METAL WIRE* Ø EQUIV. GUT TENSION**

E 0.73 mm / 0.66 mm 8.3 kg

B 0.85 mm / 0.77 mm 6.4 kg

G 1.02 mm / 0.93 mm 5.9 kg

D 0.77 mm 0.14 mm 1.47 mm 8.2 kg

A 0.91 mm 0.22 mm 1.80 mm 7.5 kg

E 1.12 mm 0.33 mm 2.40 mm 6.9 kg

Hannabach Series 728 MT, Medium Tension, black:
NOTE Ø STRING Ø METAL WIRE* Ø EQUIV. GUT TENSION**

E 0.71 mm / 0.64 mm 7.8 kg

B 0.83 mm / 0.75 mm 6.0 kg

G 1.01 mm / 0.92 mm 5.7 kg

D 0.75 mm 0.15 mm 1.46 mm 8.1 kg

A 0.93 mm 0.24 mm 1.93 mm 7.9 kg

E 1.12 mm 0.34 mm 2.45 mm 7.2 kg

Hannabach Series 8271 HT High Tension, blue “flamenco” envelope:
NOTE Ø STRING Ø METAL WIRE* Ø EQUIV. GUT TENSION**

E 0.76 mm / 0.69 mm 9.1 kg

B 0.85 mm / 0.77 mm 6.4 kg

G 1.07 mm / 0.97 mm 6.4 kg

D 0.76 mm 0.15 mm 1.51 mm 8.6 kg

A 0.95 mm 0.24 mm 1.97 mm 8.3 kg

E 1.13 mm 0.34 mm 2.48 mm 7.3 kg

Hannabach Series 900 Medium Tension, pink envelope:
NOTE Ø STRING Ø METAL WIRE* Ø EQUIV. GUT TENSION**

E 0.72 mm / 0.65 mm 8.1 kg

B 0.84 mm / 0.76 mm 6.2 kg

G 1.05 mm / 0.95 mm 6.1 kg

D 0.75 mm 0.14 mm 1.48 mm 8.3 kg

A 0.93 mm 0.23 mm 1.95 mm 8.1 kg

E 1.12 mm 0.34 mm 2.46 mm 7.2 kg

Augustine Light Tension, black envelope:
NOTE Ø STRING Ø METAL WIRE* Ø EQUIV. GUT TENSION**

E 0.75 mm / 0.68 mm 8.3 kg

B 0.84 mm / 0.77 mm 6.4 kg

G 1.06 mm / 0.97 mm 6.4 kg

D 0.76 mm 0.13 mm 1.40 mm 8.2 kg

A 0.85 mm 0.17 mm 1.90 mm 7.5 kg

E 1.13 mm 0.28 mm 2.35 mm 6.9 kg

Augustine Heavy Tension, blue envelope:
NOTE Ø STRING Ø METAL WIRE* Ø EQUIV. GUT TENSION**

E 0.72 mm / 0.66 mm 8.3 kg

B 0.83 mm / 0.76 mm 6.2 kg

G 1.00 mm / 0.91 mm 5.9 kg

D 0.77 mm 0.15 mm 1.44 mm 8.2 kg

A 0.94 mm 0.24 mm 2.01 mm 7.5 kg

E 1.13 mm 0.34 mm 2.48 mm 7.3 kg

Savarez-Alliance 540 RH, High Tension:
NOTE Ø STRING Ø METAL WIRE* Ø EQUIV. GUT TENSION**

E 0.63 mm PVDF / 0.74 mm 10.5 kg

B 0.69 mm PVDF / 0.81 mm 7.0 kg

G 0.84 mm PVDF / 0.98 mm 6.5 kg

D 0.76 mm 0.14 mm 1.48 mm 8.3 kg

A 0.84 mm 0.23 mm 1.79 mm 6.8 kg

E 1.09 mm 0.34 mm 2.42 mm 7.0 kg

(PVDF density = 1.78 g/cm³)

D’Addario Compositum High Tension, yellow/black envelope:
NOTE Ø STRING Ø METAL WIRE* Ø EQUIV. GUT TENSION**

E 0.71 mm / 0.64 mm 7.8 kg

B 0.83 mm / 0.75 mm 6.0 kg

G 1.04 mm / 0.94 mm 6.0 kg

D 0.74 mm 0.13 mm 1.43 mm 7.7 kg

A 0.94 mm 0.22 mm 1.98 mm 8.3 kg

E 1.16 mm 0.33 mm 2.55 mm 7.7 kg

Here are some further considerations. The first pertains to the pitch standard, which stabilized (almost) definitively at 440 Hz. As for the vibrating length, it remains largely unchanged from that of the Torres guitar, barring exceptions.
We have plotted the working tension trends for the treble and bass strings of the aforementioned sets in Graphs 1 and 2, respectively.

Observations:
What undoubtedly stands out most in these modern sets is the even more pronounced graduation of working tensions compared to those reported by Pujol, resembling those of the 19th-century violin. These tensions are further divided—within the same set—into two independent trends, pertaining either to the three treble strings (nylon/PVDF) or the three wound basses.
The purpose of such a peculiar tension profile, which is remarkably consistent across brands, is to optimally restore an even tactile sensation of stiffness across all strings. Note the typical tension value trend for all strings in a set in Graph 3.
It is particularly curious (if not disconcerting) that the tension range between the extreme sets (‘Light’ and ‘Heavy’) of the same model fails to exceed a semitone. Additionally, some strings in the ‘Light’ version prove to be more taut than those in the ‘Medium’ version, and—dulcis in fundo—the diameters, tensions, etc., printed on some packaging do not correspond at all to the actual string gauges, as determined by precise laboratory measurements. In other words, tensions and diameters often differ significantly from what is stated on the envelopes. For example, taking the equivalent gut diameter of the low E in the Hannabach ‘Low Tension’ series, it is 2.41 mm. If raised by a semitone (approaching what could almost be considered a Medium Tension), it would reach an equivalent gut diameter of 2.55 mm. Yet, in the ‘High Tension’ series—the highest tension—it only reaches 2.48 mm: a mere quarter-tone above the ‘Low Tension.’ Can this truly be called a Heavy Tension? Similarly, with the two Augustine sets examined, the nylon treble strings in the ‘Light’ tension are actually thicker than those in the ‘Heavy’ tension. For the three basses, things proceed smoothly, except that here, too, the difference between the extreme tension grades barely reaches a quarter-tone. For the most meticulous readers, we clarify that the diameter and weight measurements of commercial strings were conducted with a calibrated precision micrometer, while the weights of wound strings—whose equivalent gut diameter is derived through simple calculations—were obtained using a microanalysis balance accurate to the fifth decimal place, under constant humidity conditions.

For completeness, it should be noted that treble strings inherently exhibit a degree of ovalization and gauge inconsistency along their length—a consequence of starting with a molten material that is extruded to size and then cooled. This was an entirely unfamiliar issue with gut strings. Similarly, for bass strings, there is always some fluctuation in the produced gauge, depending on the worker’s skill in consistently applying the same tension to the metal wire during the winding process onto the tensioned and rotating nylon core. Experimental tests have shown that such fluctuation (when intentionally pushed to extremes) can result in up to a quarter-tone difference in tension between two supposedly identical strings (i.e., made from the same amount of core and the same metal wire), where the wire was wound with minimal tension in one case and greater tension in the other.
This reality, which undeniably exists, undoubtedly raises serious questions for those who delight in devising ingenious and often complex strategies to position guitar frets for so-called perfect intonation.
Gut strings, which did not suffer from ovalization, were instead quite soft, making them highly susceptible to wear from the right-hand fingernails and metal frets. This issue is negligible with nylon and carbon strings, which are far harder than gut.

Final Recap

At this point, it seems sufficiently clear that the string setups and types used in the past consistently followed criteria fundamentally different from those commonly applied today to Baroque, Romantic, and early 20th-century guitars. This may partly explain the thinness of sound produced by these instruments today. Regarding the guitar of the “Age of Enlightenment,” it is evident that we are dealing with an entirely different world—not only from a purely organological and musical perspective but also in terms of tuning, string types, and gauges involved. Beyond its constructional affinity with more recently built single-string instruments, it appears almost as a wholly distinct instrument from that of the following century. As for the latter, it actually employed string diameters far larger than previously assumed, with an essentially equal tension distribution across the strings and, moreover, silk-wound basses.
The strings themselves, as noted, were likely quite different from today’s gut strings, whose current production often yields excessively rigid strings (and rigidity negatively impacts sound quality). In contrast, Italian and French production of the time aimed to produce far more elastic gut strings, thus achieving superior acoustic performance. It should also be recalled that, unlike today, musicians of that era could easily distinguish by touch and sight a good string from a bad one, a skill that now seems almost entirely lost. Furthermore, one could select stronger or weaker string setups—depending on personal taste and instrument type—simply by choosing from the usual packaging (marked with numbering indicating the number of strands composing all the strings in the set) and using the appropriate string gauge to find the desired strings. With the evolution of the guitar in the late 19th century (Torres), the criteria for selecting a string setup shifted toward the use of thinner diameters compared to the 19th century.
However, the most substantial difference from the previous century lies in the tension profile across the strings: now graduated, it allows for the recovery of a uniform tactile sensation of stiffness, which had been the guiding criterion in the centuries preceding the 19th.
Nevertheless, it should be observed that a reduction in gauges by about a semitone in tension is accompanied by an increase in vibrating length, also by about a semitone. Consequently, due to this compensatory phenomenon, the average total tension value neither increased nor decreased significantly. Diameter and vibrating length are, after all, inversely proportional to working tension.
As for the bass strings, while they were predominantly made of wound gut in the 18th century, with the advent of the six-single-string guitar, they were always crafted using silk, prioritizing—at the same equivalent gut gauge—the maximum predominance of metal over silk. It is believed that silk basses—which undoubtedly offer better acoustic performance than those with gut cores—may have played a role in the “launch” of the smaller six-string guitar, though they cannot remotely compare to nylon cores.
With the advent of nylon, a veritable Copernican revolution ensued—one that no one could have predicted—accompanied, however, by a certain productive leveling due to the standardized sourcing of nylon monofilament and multifilament. Unlike gut, these materials are now mass-produced—and in rigidly defined sizes—by multinational patent holders, typically Japanese (for carbon) or American (for nylon). Commercial guitar string sets inevitably exhibit strong similarities and only partially align with those in use in the first half of the 20th century, particularly in the tension profile of the first three strings.
The situation differs for basses with synthetic multifilament cores: thanks to their superior mechanical properties, their acoustic performance far surpasses that of silk. Much of the “percussive” effect typical of silk-core strings disappears, replaced by greater output power, richer upper harmonics—though not always desired—and sustained sound.
A true upheaval, then: percussive, harmonically poor basses with brilliant trebles until 1948, followed by brilliant, sustained basses but more muted trebles in the subsequent decades.
Yet research has not forgotten gut: current efforts are heavily focused on developing materials that replicate its characteristic acoustic performance without the drawbacks overcome by nylon, such as high cost, climatic instability, and short lifespan. Thus, new products have emerged, such as the aforementioned PVDF for treble strings, new types of nylon (more transparent and sonorous, like Cristal, made of polyamide 12), and, more recently, Nylgut, a synthetic material newly applied to music. With its translucent white color and the same density as gut, Nylgut represents, in some ways, the most representative synthetic version of gut, offering an acoustic output extremely similar—if not identical—to it. However, it has the drawback of being rather soft compared to nylon and carbon (as gut itself is). Recently, Nylgut in multifilament form—owing to its high tensile strength—has enabled a further reduction in core size for basses, favoring a greater metal content. This has paved the way for a new generation of wound strings with remarkable overall performance and significantly smaller external diameters, especially when made with pure silver. In other words, a low E string can now have a diameter only slightly larger than a traditional nylon A string. The core diameter of a low E with equivalent tension has progressively decreased from 0.67–0.74 mm, typical of silk cores, to 0.44–0.50 mm with nylon, and now to 0.30–0.35 mm with Nylgut cores.

Conclusions

The history of string makers, unlike that of their luthier and musician counterparts, was largely marked by near-total anonymity.
Many of them were illiterate, and their humble workshops were pushed out of urban centers without much regard due to the frankly nauseating odor their production entailed. Little is known of their private lives, and even less of their trade secrets. It is even harder for us to acknowledge that the noble art of music relied for millennia on such repulsive material: animal gut.
Yet string makers deserve credit for making plucked and bowed sounds possible and, above all, controllable and reproducible—enough to enable the greatness of Bach, Torres, Segovia, and even the simple amateur to express their poetry.
The impetus Andrés Segovia gave to the development of synthetic materials was utterly irresistible. The Day of Judgment for gut had definitively arrived. In the Maestro’s writings from those frenetic years of experimentation, a palpable bitterness emerges from a great performer—who he truly was—fed up with strings that frayed during concerts, were costly, of variable quality, and subject to climatic whims: “Those of my generation who devoted themselves, as professionals or amateurs, to the guitar will recall, as I do, how much we suffered when we had only gut and silk strings, despite the valiant efforts of the directors of Pirastro or Hermann Hauser, for instance, who brought their products to the highest degree of perfection for that time.” And again: “The strident sound of the first string, sometimes rather offensive to a sensitive ear, the lack of sweetness in the second, and the truly rough and dark timbre of the third increasingly irritated me. The sound of the fourth, fifth, and sixth strings, meanwhile, faded instantly.” With Segovia, the millennia-old symbiotic bond between plucked musical instruments and natural materials like gut and silk was severed forever. But, as often happens with those fiercely dedicated to a significant cause, he forgot to remind posterity of the virtues buried in what he opposed—specifically, the characteristic that makes gut an utterly unique material, almost endowed with a soul: its irresistible tendency toward “vocality,” the imitation of the human voice.

109. STEFANO GRONDONA – LUCA WALDNER, La chitarra di liuteria, L’Officina del Libro, Sondrio, 2001
110. It suffices to note that, to this day, Italy has only three centers producing gut strings for musical use, located in Salle, Vicenza, and Naples.
111. LUIGI FORINO, Il violoncello, il violoncellista ed i violoncellisti, Hoepli, Milano, 1930, 2nd ed., p. 55: “German strings have the advantage of durability and, like all products from that nation, also that of a good price. They are extremely polished, hard to the touch, almost like steel: their sound reflects this hardness as well.”
112. EMILIO PUJOL, Escuela Razonada de la Guitarra, basada en los principios de la técnica de Tárrega, Libro Primero, Ricordi Americana, Buenos Aires, 1934, p. 33. The Escuela was published in 1934, but its composition almost certainly dates to the late 1920s. The string measurements provided likely cover this historical period as well.
113. CARL FLESH, The Art of Violin Playing, 2 vols., Fischer, New York, 1924-30 (original edition, Die Kunst des Violinspiels, 2 vols., Ries, Berlin, 1924-8).
114. The manufacture of particularly ‘hard’ strings might be explained by an attempt to increase their durability and tuning stability, albeit at the expense of sound quality. This may be how most patents related to gut string manufacturing from this period—especially by German researchers—should be interpreted.
115. ANDRÉS SEGOVIA, Guitar Strings Before and After Albert Augustine, “Society of the Classical Guitar,” New York, 15 October 1954.
116. See the DuPont Company Home Page (www.DuPont.com) under “Polyamide.”
117. Private communication to the author from Richard Cocco, president of E.O. Mari Inc., 2001.
118. See the DuPont Company Home Page under “Tynex.”
119. FRANZ JANHEL, Die Gitarre und ihr Bau, Verlag Das Musikinstrument, Frankfurt am Main, 1977.
120. The string packages on which we performed the measurements reported here were purchased by us in 2000 from a music accessory shop in Vicenza.