Cat Gut Strings. The Dark History of Violin Strings

History of Catgut Strings

The origins of using cat gut for musical instrument strings dates back to the 15th century in Italy, when lute players found that strings made from cat intestines created a superior tone compared to other materials like metal or silk.

lute player with cat gut strings from 15th century

Catgut strings quickly became the preferred material for lute, harp, and violin strings across Europe in the 16th and 17th centuries. They were made from the intestines of sheep, horses, and cows, despite the name “catgut.” According to WQXR, the term catgut may have originated from the Italian word “catarrh” meaning “bowels.”

The use of genuine cat gut was rare and limited. However catgut strings remained the dominant type of string used by classical musicians until the 20th century. By the 1940s, most musicians transitioned to using nylon and steel strings, which project greater volume with more stability.

Manufacturing Process

Catgut strings are made from the intestines of cats and sheep. The intestines contain collagen fibers that can be turned into musical strings. Here is an overview of the manufacturing process:

The raw materials used are the small intestines of cats and sheep. These intestines are collected from slaughterhouses and carefully cleaned. The fat and membranes are removed from the intestines in a process called scrapping. What remains is just the collagen fibers.

Next, the collagen fibers go through a spinning process to align the fibers and turn them into a strong, thin thread. This thread can then be twisted and wrapped around itself to create thicker strings.

The strings are then polished and treated. They may be bleached or dyed to get the desired color. The strings are also treated with special solutions that help preserve and strengthen them. For example, treating them with sulfur helps repel moisture.

After the chemical treatments, the strings are calibrated to achieve the proper thickness and tension for their intended purpose. The finished strings are then wound around pegs and packaged.

It’s a time and labor-intensive process, but produces strings with excellent acoustic properties. The purity of the natural catgut fibers results in strings with a warm, mellow tone.

Properties of Catgut

Catgut has been used for musical instrument strings for centuries due to its unique properties that make it well-suited for the task. The main advantages of catgut as a string material are its strength, elasticity, and warm, rich tone.

Catgut strings have just the right blend of stiffness and elasticity to vibrate and produce sound waves when played. The proteins in catgut allow it to stretch under tension but quickly return to its original length. This gives catgut excellent responsiveness while maintaining proper string tension and pitch.

violinist playing instrument with cat gut strings

In addition to mechanical properties, catgut strings also produce a warm, mellow tone with a lot of depth and complexity to the sound. The natural fibers and proteins in catgut seem to resonate sympathetically with the wood of instruments like violins and guitars. This gives catgut a timbre that many musicians feel sounds superior to synthetic strings.

The right combination of strength, elasticity, and tonal richness makes catgut an ideal and sonically pleasing material for the strings that translate a musician’s artistry into audible sound.

Alternatives to Catgut

While catgut was historically the main material used for violin strings, alternatives emerged over time. The most common modern violin string materials include:

  • Steel – Used for the G string due to its strength and stability. Steel has a bright, projecting sound.
  • Silver-plated steel – Also commonly used for G strings. The silver plating warms the tone compared to raw steel.
  • Synthetic core strings – Most often utilizing Perlon or polyurethane fibers. These aim to emulate the playing qualities of gut while improving durability and consistency.
  • Nylon – Has a warm, mellow sound but with more sustain than gut. The Pirastro Tonica line uses nylon.

Compared to catgut, synthetic materials offer more tuning stability and weather resistance. However, many players feel catgut provides a richer, more nuanced sound. As this thread notes, catgut conveys subtle overtones and colors not present in synthetics. Others argue this is primarily psychological, and modern manufacturing can mimic gut.

For players seeking a traditional baroque sound, catgut may be preferred. As this forum post explains, catgut has a “warm, softly percussive, immediate tone” unlike nylon. However, nylon provides more volume and sustain. Ultimately the choice depends on the desired tone and historical accuracy.

Use in Modern Times

While catgut strings are not as commonly used today as synthetic strings, they still have a loyal following among certain musicians. Classical string players, particularly those who play baroque or early music on period instruments, often prefer the warm, organic sound of real gut strings.

Catgut strings are made from sheep or goat intestine and have a mellow, smooth sound quality. However, they are more susceptible to pitch fluctuations and breakage compared to steel and synthetic strings. Gut strings also tend to be more expensive and high maintenance – they don’t last as long and need to be replaced more frequently.

For modern instruments like violins and guitars, most players opt for steel and synthetic strings, which offer greater tuning stability, durability, and affordability. But catgut remains popular for instruments like the harp, lute, viola da gamba, and baroque violin and cello. While niche, they continue to be produced and used by those seeking an authentic, historical sound.


Cultural Significance

Catgut has a long history of being used for musical instrument strings, especially for stringed instruments like the violin, viola, cello, and double bass. Many famous composers and musicians through history have used catgut strings on their instruments. Sources cite cultural traditions around the use of catgut:

“Catgut has been an indispensable part of string music for centuries. Many famous violinists and composers including Paganini, Mozart, and Beethoven used catgut strings” (Wikipedia).

“Before 1900, there were no nylon and metal strings – strings were made exclusively from animal intestines. Cello strings would have a sheep gut ‘G’ string, sheep gut or steel ‘D’ string, and wound sheep ‘A’ and ‘C’ strings” (Amorim Fine Violins).

The preference for catgut strings was partly due to the tonal qualities and playing characteristics. Many prominent musicians and composers have valued the sound of catgut strings on violins and other stringed instruments.

Ethical Concerns

The use of catgut for violin strings has raised ethical concerns, primarily surrounding animal welfare. Traditionally, catgut was made from the intestines of cats, sheep, and other animals. This process involved slaughtering the animals solely to source the raw material for strings. Today, most commercial catgut comes from the intestines of cows and sheep slaughtered for meat production. However, some small suppliers still source from animals killed specifically for their gut material (Morality Is Like A Catgut String).

peta protest against using cat gut for strings

Many animal rights groups, such as PETA, consider the use of animal-derived catgut unethical and have called for alternative materials. They argue that relying on animal sources is cruel, given viable synthetic substitutes exist. Regulations around catgut production and animal sourcing vary greatly by region. In the EU, for example, gut string production is regulated by laws surrounding animal byproducts from the meat industry.

In response to ethical concerns, most violinists today use synthetic strings instead of catgut. Popular alternatives include nylon, steel, and various polymer materials, which replicate the tonal qualities of gut. These allow players to avoid relying on controversial animal-derived materials. While gut strings retain a small niche market, the majority of violinists opt for ethical, high-performing synthetics instead (Do musical instruments utilize animal products?).

Sound Profile of Catgut Strings

Catgut has a warm, rich tone that enhances the acoustics of stringed instruments like the violin, cello, guitar, and harp. The organic material vibrates naturally, producing complex overtones that fill out the sound. This gives catgut strings a singing, vocal-like quality.

The flexibility of catgut also allows for more subtle tonal variations and nuanced expression by the musician. Compared to metal strings, catgut softens the attack while still letting notes speak clearly. The strings vibrate for a sustained period, enabling a smoother legato sound.

Modern synthetic strings aim to emulate the acoustic properties of catgut. However, many musicians argue that nothing truly matches the resonance and warm tone provided by real catgut. The natural responsiveness and harmonic richness remain appealing, especially for soloists and chamber groups seeking to achieve a refined, sensitive sound.

Cost Considerations

Catgut strings tend to be more expensive than synthetic alternatives. This higher cost is due to several factors:

Catgut strings must be handmade in a time-intensive process, requiring skilled craftsmanship. The labor involved increases production costs.

expensive specialty cat gut violin strings for sale

Sourcing quality cat gut and treating it for use as musical strings adds to material expenses.

As catgut strings have become less common, economies of scale have been lost. With smaller production volumes, costs per unit are higher.

The niche status of catgut strings makes them a specialty product geared toward high-end instruments and discerning musicians. This allows retailers to command premium pricing.

With continued competition from synthetic strings, catgut string prices have steadily risen. Many musicians view their premium tone as justifying the extra investment.


In summary, catgut was once a very common material used for stringing musical instruments like violins, but its use has declined over time. While cat gut provided certain tonal qualities that were appealing to musicians historically, the material also had drawbacks like sensitivity to changes in temperature and humidity. The use of catgut raises ethical concerns as well about the treatment of cats.

Modern instrumentalists have largely switched to using steel and synthetic strings, which provide more durability and stability. However, some musicians still prefer the sound of catgut for their string instruments. Overall, each type of string material carries its own strengths and weaknesses. The choice often comes down to the sound characteristics and playing qualities desired by each individual musician. While catgut is not obsolete, it has become more of a niche choice today.

When evaluating the merits of various string materials for instruments, musicians must weigh factors like sound quality, longevity, tuning stability and personal ethics. There is no universally superior option, but rather different solutions suit different instruments and artists. The history of catgut reminds us that older methods often give way to new technologies, but traditional practices can still persist alongside modern ones, especially in fields so intrinsically tied to craft, tradition and personal preference like music.

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