In the olden days, musical instrument strings were made from the intestines of sheep. For some unknown reasons, the term catgut was used to refer to these strings.

Even today, some violin strings are made of sheep gut. The same craft guilds made strings for tennis and badminton racquets in those times.

Metal wire strings are in use, since the late Middle Ages, for heavier musical instruments like harpsichords, lutes, and mandolins. For lighter instruments like guitar, gut strings were used, due to the lower strength of the instrument. In the 19th century, the development of bracing coupled with improvements in guitar anatomy and other design improvements resulted in guitars becoming stronger and larger in size.

By the 1880s, some of the guitars had become heavy enough, to withstand the tension exerted by the steel strings. This is when steel strings started to become popular for acoustic guitars. Gut strings were still used by classical guitarists, till the advent of nylon strings in the late 1940s. Steel strings are not preferred by classical guitarists due to their tone, handling, and thin & jangly sound.

Selection Of String

The major factors on which the choice of any string depends, are

1. String gauge – This refers to the diameter of the string, which determines the effort required in pressing the string.
2. Material and construction – This is related to

For absolute beginners, starting with acoustic guitars, it is recommended to use light (0.012 to 0.053) gauge, 80 / 20 bronze wound new strings.

Introduction To Steel Strings

Steel strings come in different construction and gauges. In flattop, six string acoustic guitars, 1st  and 2nd  strings (High E and B), are plain stainless steel wires. 3rd to 6th strings have a steel core, overwound with fine brass or bronze wires. This type of construction is called wound strings.

For a given length and tension, the frequency of vibration of the string is inversely proportional to its mass. More is the mass of the string; its fundamental frequency of vibration or pitch will be lower. As lower strings (3^rd to 6^th) have to produce lower pitches, their mass is increased by making them wound.

Another choice was to have solid wires with increased mass and diameter. But thicker wires lose their elasticity and do not vibrate properly. Winding is done on all steel guitar strings of diameter, more than 0.021 inches.

Types Of Steel Strings 

Steel strings can be classified into the following main categories

• Bronze wound strings for Acoustic Guitars
• Nickel wound strings for electric guitars.
• Compound Strings
• Coated Strings

Let us look in detail, at each of the above categories

Bronze Wound Strings

Brass and Bronze wound strings are both generally referred to as Bronze strings in the music industry. Both of these strings are used on acoustic flattop guitars. Brass is an alloy of Copper and Zinc, while Bronze is an alloy of Copper and Tin.

80 / 20 designated strings are 80 percent Copper and 20 percent Zinc. Similarly, 60 / 40 designated strings are 60 percent Copper and 40 percent Zinc. The more the percentage of Zinc, the brighter the sound of the string.

Strings called Phosphor Bronze are true bronze strings. They have 90% percent Copper and 10% Tin. A small fraction of phosphorous is added to increase the life of the strings, even though it increases the cost. In terms of sound, Phosphor strings are warmest and softest, 80/20 is midway while 60/40 is the coldest and most bright.

Nickel Wound Strings

Nickel wound strings are used for Electrical Guitars. These are similar to Acoustic Guitar strings except for the difference in the materials. For magnetic pickups to work better, we need to use strings with magnetic properties. To achieve this, the strings are made from Nickel-plated Steel, Pure Nickel, or Nickel Iron alloy.

Nickel plating balances out the bright sound of steel keeps the string smooth and protect them from corrosion.

Pure Nickel strings have a warm and mellower sound than Steel or Nickel plated strings, making them more suitable for classic rock, Jazz, or Blues music.  

Nickel strings are much less resonant than bronze strings if used on acoustic guitar without any sort of amplification. If a pickup is placed on an acoustic guitar, it will only work properly, if we have Nickel or Copper plated strings.

Nickel wound strings have a longer life in comparison to Bronze. However, being harder metal, their use will wear down frets much faster.

Compound Strings

The construction of the compound string set is as follows:

• The first two strings are regular steel strings, a little lighter than standard light-gauge ones.
• The lower four strings have a much thinner core. The core has additional micro-filament made from Nylon floss. This addition increases the mass of the string and lowers its tension making it much easier to play. The tone from these strings is warm and sweet with soft volume.
• These are labeled as Steel and Silk strings, even though there are no Silk microfilaments now. In olden times Silk was used instead of Nylon.

The compound strings are better for beginners due to their lower tensions. They also exert lower string tension on the bridge. Hence, these are preferred strings for twelve-string and delicately built guitars. Their tension is still much higher than the safe withstanding capabilities of classical guitars.

Coated Strings

Coated strings come in two varieties. They are either coated with materials like PolyWeb or with copper. Let us briefly take a look at both of them.

PolyWeb Coating

Bronze strings coated with PolyWeb material are made by Elixir brand strings, which is a division of W. L. Gore company. These strings produce a warm sound that does not change during their life. Some guitar players have very acidic perspiration, which causes string corrosion. This coating inhibits the corrosion and gives a smooth & easy feel on the fingers and reduces finger squeaks.

Copper Coated Strings

The use of copper-coated strings has reduced over the years due to technological changes. These were used for acoustic guitars with magnetic pickups of earlier times. These pickups were designed to work with nickel and did not work well with bronze wound strings.

Steel strings were coated with copper to overcome the problem. Typically, around 30% of the string mass was copper in such strings. In modern times, the pickups designed for acoustic guitars are capable of picking up the vibrations of bronze wound strings effectively, rendering these strings unnecessary.

Shape of Winding

All guitarists like smoother strings with no or very less squeaking. Some of the ways to achieve this are to move your fingers very lightly along the strings or to use spray-on lubricants like Finger-Ease or similar. The shape of the Winding also plays an important role in achieving the above objectives.

Strings are made by a process called drawing, in which the metal is passed through a series of holes in the dies. The diameter of the holes is decreased in each step to make the wire thinner. The wires for the first and second strings of the guitar are circular in shape.  But the wire, that will be used as a core for the wound strings, it passes through a hexagonal die in the last step.

This provides a better gripping surface for the Winding. These types of wound strings are also called hex-wound or hex-core strings. Finally, the core is placed on a lathe machine and rotated, while the finer bronze or brass winding is wrapped around it tightly.

The profile of the wound wire, in addition to the feel, also affects the tone. We shall now see common shapes of Winding used in the industry.

Roundwound Or Regular Strings

These strings have the brightest and punchy sound out of all wound ones, but more noise due to space between the turns. These are good for rock guitars.

In this type, a round wire is wrapped around the hexagonal or round core, giving a little bumpy feel. This bumpy profile results in more friction on the fingertips of the player and produces a squeaky sound on sliding fingers over the strings. The squeaking effect is more pronounced with a guitar amplifier or PA System.

The higher friction causes a faster fingerboard and frets wear. In case of small damage to the winding, it becomes less secured and may start rotating around the core freely. 

One of the options to overcome the above drawbacks is the use of coated strings with PolyWeb / NanoWeb coatings discussed in Coated strings section above.

Flatwound Strings.

A flat wire ribbon is wound over the core in this type of string. The sound is quite dull and not particularly preferred by acoustic guitarists. It works better on electric and bass guitars. Flatwound strings have much lower flexibility than regular strings.

These strings are more suited for Blues and Jazz music and have the warmest sound of all the strings.

Some of the Pros of Flatwound strings include

• Smoother Surface. Good on hand, particularly in humid surroundings and longer sessions.
• Fewer squeaks
• Less fret wears
• The tone is consistent during the string life.
• Mellow sounds similar to many big body Jazz guitars.
• Suited for Humbucker pickups as they provide volume/touch sensitivity.
• Longer life

Some of the Cons of Flatwound strings include

• More expensive
• Unavailable in smaller gauges
• More tension than Roundwound type. This also makes them difficult to bend.
• Narrow Frequency response with diminished higher frequencies.

Groundwound Strings 

This type of string is midway between Roundwound and Flatwound strings and can be considered a compromise between the two. It is also known by the names Halfwound, Polished or Flat Polished string.

It is manufactured as Roundwound string and the winding is then ground, pressed, or polished down to make flatter and smoother surface. To compensate for the loss of mass due to the grinding or polishing process, they are made with winding wires of higher gauge.

These are more popular among Bass guitarists due to their warmer sound, even though it has some of the sound qualities of the Roundwounds.  The sound is much brighter than the Flatwound strings and remains so during the lifetime of the strings.

The strings have a much smoother feel with less noise during the change of chords.

More: Best Guitar Strings for Metal

Nylon Strings.

The composition of the Nylon string set is

• 1^st to 3^rd (treble) strings are made from nylon microfilament.
• 4th to 6th (Bass) strings have a multifilament Nylon floss core. This core is wound with Bronze, Copper, Silver plated Copper or some other metal.

These strings were first developed by Albert Augustine Strings in 1947. Nylon strings are used on Classical guitars which are much lighter than Folk guitars. Nylon strings are unable to transmit enough energy to the top of folk guitars, hence only steel strings are used on them.

The Nylon strings are soft, less dense with much less tension (50% of steel-string guitars). Thus, if you have to restring old guitars, that are not capable to support the tension of steel strings, Nylon strings are the way to go.

Nylon strings are generally available in three levels of tension – Normal, Hard, and Extra hard.

• Normal strings are easy to play, but not suitable for louder or faster music. It has more low and low-mid-range frequencies.
• Hard strings can play louder with increased difficulty.
• Extra hard strings are for very fast & loud music. These strings have more high-end representation and attack.

Nylon strings can be attached to the bridge in two ways

• Tie End  – Most Nylon string guitars have Tie End strings. There are no ball ends or bridge pins to attach to on the bridge end. The nylon strings are slid through the bridge, wrapped around it twice, and tied to the bridge.
• Ball End – In this arrangement, there is a plastic or metal ball/bead at the end, around which the string is wound and tuned.

Materials for Nylon Strings.

Nylon strings come in three types

• Genuine Nylon – This type is the most common one and is described at the beginning of this section. They have a warm and rich tone but low volume. They facilitate vibrato more than the other two types.
• Titanium Nylon – This is made out of Titanium Nylon polymer or polyamides. The polyamide strings are called Titanium strings due to their coloration. Their sound is brighter than Nylon strings with a more metallic sound.
• Fluorocarbons – They are also referred to as Carbon Fiber. They are brighter than Nylon strings with more volume and articulate tone. They lack more sustain than nylon ones and suffer from intonation issues.

Conclusion

In this article, we have seen the history of strings, types of strings, wound, coated, and composite steel strings, shapes of winding, and Nylon strings including Genuine, Titanium Nylon, and Fluorocarbon strings. In our next article, we shall go through the gauges and tensions in the steel strings.