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The Gut Tennis String

In this article from our tennis string guide, discover everything you need to know about gut tennis strings, also called natural gut tennis string !

It is the historic string of tennis, the first to have been laid on wooden tennis rackets and still used actually, it is preferred by competitors and professional or old-school tennis players, generally laid in hybrid (uphill or across). Many consider it today, by its price and its decline in use in the history of tennis as well as its frequent use on the ATP, WTA and ITF professional circuits, as the best type of tennis string in the world, the "rolls royce" of the most versatile and comfortable tennis strings.

A look back at this iconic tennis string which is still produced today and since 1875.

The Gut Tennis String: Type & Manufacturing

The gut tennis string, historic tennis string used on tennis rackets since its invention in 1875 by the family and historic French tennis brand BABOLAT, is a multifilament type string, composed exclusively of an alloy of animal fibers (multifilaments), from bovine casings and intestines (beef, cow, etc.), chemically treated and dried to form the final string placed on tennis rackets.

 

The particularity of the natural gut tennis string lies in its very essence: 

It is indeed the only tennis string of animal origin. Its manufacture, which can always be described as artisanal, then uses "living" raw materials that are very difficult to reproduce with accuracy from synthetic fibers and rapid and mass manufacturing processes.

Thus, each gut tennis string developed and produced by a tennis brand is unique and the playing sensations of each gut tennis string can completely differ from one reference to another.

If the sensations of each gut tennis string existing on the tennis string market are unique, its manufacturing process is very rigorous and follows with very little evolution since its marketing years ago the same manufacturing principles.

The main steps in the manufacture of natural gut tennis strings are as follows:

1. Selection of bovine raw materials :The guts and intestines used for the manufacture of tennis strings generally come from cattle, most often beef and adult cows.

Brands producing natural gut tennis strings can go so far as to select a single, very specific breed or species of cattle to ensure the quality of manufacture and the durability of the sensations of the gut tennis strings produced. 

The intestines, generally fresh, received at the manufacturing plant are carefully cleaned, sorted and selected according to their quality before preparation (we check in particular the general appearance, the porosity, the color, the fragility and the possible tears or scars of the walls , freshness of the intestines, etc. as eliminatory criteria).

At UNI-CORD®, for the production of our THE GUT 1.31 gut tennis string, nearly 15% of the beef intestines received by the partner manufacturing plant are eliminated before the start of production of the tennis string.

2. Preparing the casings : The casings selected for the production of tennis strings are first washed with plenty of water to remove any impurities and residue on the surface and inside.

Then they are soaked in a saline solution with various chemical treatment agents to preserve and hydrate the fibers before construction of the "strand" filaments forming the gut tennis string.

The casing being a raw material of animal origin, it degrades quickly. To treat bovine gut before manufacturing tennis strings, manufacturing plants must use preservatives

anti-fungal, anti-bacterial and anti-microbial to anticipate any natural degradation of the casings or prevent any formation of micro-organisms that could destroy the casing and its fibres.

Treatment agents include Chlorhexidine for bacteria and/or Benzalkonium Chloride for microbes.

The gut is also a very elastic material, it is the very origin of the unequaled comfort of the gut tennis string which the tennis players love. To maintain the elasticity of the guts throughout the manufacture of the tennis string, the manufacturing plants must use anti-UV or hydration agents to prevent the natural and premature drying of the animal fibers but also to maintain a rate of humidity of the gut protecting its flexibility throughout the manufacturing process of the tennis string.

Among the treatment agents, Benzophenone can be used as a chemical UV filter and Glycerol to maintain the humidity of animal fibers and stabilize their elasticity. 

3. Degumming : The degumming process consists of removing the natural gum present in the casings. This is done by using special enzymes and solutions that break down the rubber, leaving the gut fibers ready for the formation of tennis strings.

4. Cutting and sizing : The casings are then cut into sections of equal length. . Then, the sections are calibrated to obtain uniform diameters, which is essential for the regularity of the final string and the maintenance of the good gauge of this one. It is a delicate process that requires precise cutting and carried out by skilled workers with artisanal know-how. This is one of the reasons why natural gut tennis strings are more expensive to purchase than monofilament, multifilament or even synthetic gut tennis strings.

On the tennis string market, the thicker the gut tennis string with a large gauge (around 1.40), the more economical and less expensive it is to buy.

At UNI-CORD, our THE GUT 1.31 gut tennis string has a rather thin and qualitative gauge when you know that the average gauge of gut tennis strings on the market is 1.35.

5. Twist: The sections of casing are twisted to form individual strands, the filaments. The natural gut tennis string is therefore also a multifilament tennis string. This twist in the gut tennis string contributes not only to its elasticity and comfort in play, but also to the resistance to breakage and the tension holding of the final string. It's a step essential in the manufacture of gut tennis strings.

 

6. Assembly of the strands: Several individual strands are assembled to form the core of the string. The number of strands used can vary depending on the specifications of the desired string and its general manufacturing quality, but also depending on the gauge of the final tennis string to be produced.

As a general rule,  The thicker the gauge of the gut string, the more the braiding is spaced out if you want to use fewer additional strands to increase the thickness of the string, this has a direct impact on the price of the gut tennis string produced.  The more strands the natural gut tennis string required during its manufacture, the higher its purchase price.

These principles are the same for multifilament tennis strings, which simply use individual synthetic filaments, usually nylon.

7. Strand twist and wrap: The assembled strands are twisted together to form the basic rope. This twist can be done in opposite or specific directions to balance the internal forces of the string and adjust its performance or resistance.

The way the filaments are braided is specific to each brand that manufactures gut tennis strings.

The cover of the natural gut tennis string, optional, is one of the rare and small evolutions that has known the manufacture of this historic tennis string.

Today, most of the gut tennis strings produced by brands have a cover and are therefore of the "Coated" type. Conversely, the gut tennis string without cover is Original or "Uncoated".

8. Drying: The produced gut tennis string is then dried to evaporate any remaining moisture.

This helps to stabilize the properties of the string and its structure. It therefore observes a period of rest before tension and is generally kept cool in a cold room.

9. Tension and stabilization: Once the gut tennis string has dried and rested, it is stretched to one or more specific so-called control tensions, and for a certain time, to stabilize its internal structure and its elasticity. Before packaging and marketing, all tennis strings produced in the manufacturing plant undergo preliminary tensioning, which also acts as a quality control before the tennis string is used by the stringer and his individual stringing machine.

10. Finishing & Packaging : After control tensioning and stabilization, cach tennis string is manually inspected for any defects or irregularities.Tennis strings that do not pass inspection are rejected from sale. In the case of gut tennis strings, a garnishwhich would have yellowed or whitened too much during its manufacture, or which would not be smooth enough on the surface, could be rejected from packaging and marketing. All these sorting steps, which are particularly numerous and strict on gut tennis strings, contribute to having more losses in the factory on this type of tennis string,slower production and lower production volumes, and thus a much higher selling price than for other types of tennis strings.

The finished gut tennis stringst cut and rolled up on itself to the desired selling length. Its yardage generally follows that of other tennis string sets, either12 meters. It can be cut into a single gtrim of 12 meters or in two half trims of 6 meters.

A 12 meter single full trim cut gut tennis string may be laid through the uprights and crossways of the racquet by the stringer with a two knot tennis string laying method although this is not recommended.

A gut tennis string cut into two 6-meter half-pieces can only be laid with a method of laying tennis string in 4 knots in the uprights and across the racket by the stringer.

Laying a gut tennis string in full set (12 meters of gut tennis string on the same racquet, upright and across) is of little interest. Today the gut tennis string is used almost exclusively for the installation of a classic or inverted hybrid tennis string, hence the democratization of the sale by the half set in a 6-meter set or the cut of the gut tennis string in two sets of 6 meters on the trims of 12 meters.

 

Tennis strings that have passed quality controls are carefully packaged and ready for distribution to players and tennis stores. Each natural gut tennis string is packaged in the form of an insulated pouch, each containing a complete unit set of 12 meters (for a racket) or a half set of 6 meters (for stringing the uprights or crossbars only of the racket, in the form of a hybrid tennis string). 

On the other hand, there is no gut tennis string sold in reels of 100 or 200 meters.

Indeed, the gut tennis string, in addition to its high price per set (12 and/or 6 meters) is not relevant for public sale in large quantities. Also, the gut tennis string requires special insulated packaging which protects it from heat and light throughout its storage period with the player before it is placed on the tennis racket.

All of these steps illustrate the general process of making a gut tennis string. Each step requires expertise and meticulous attention to produce a high-quality string that is loved by professional and amateur players alike. The noble character of such manufacturing also makes gut tennis strings a very popular choice and recognized as a guarantee of quality by all tennis players.

Cordage Raquette Tennis - Court de Tennis UNI-CORD

The Cheap Gut Tennis String type "Coated Natural Gut"
THE GUT by UNI-CORD® - MADE IN EUROPE

The Gut Tennis String: Properties and Contribution to the game

The advantages of gut tennis strings are numerous, in particular comfort and power unmatched by other types of monofilament, Synthetic Gut or multifilament tennis strings, hence the choice of competitors and professionals to still use this type of tennis string today. today most often in hybrid with a monofilament, despite the installation of the modern game at maximum spin, due to greater comfort and better absorption of strikes and the explosive return of the gut, i.e. properties and always interesting sensations for the modern game of tennis and a high frequency of tennis practice.

The natural gut tennis string is also the multifilament tennis string that has the greatest tension resistance, so it protects the arm and lasts longer than other types of tennis string.

The collagen of animal origin that it contains, derived from the serosa of cattle, gives it elasticity and therefore absorption of hits and extraordinary comfort, unique properties and rarely equaled by the best multifilament tennis strings on the market.

TO WHOM TO ADVISE IT AGAINST?

It is important to remember that a gut tennis string remains more expensive to use, and will be of little relevance and recommendable for tennis players on a low budget and those with an ultra modern game, fans of big lifts and extreme racquet grips: the breakage of the gut tennis string with this type of game will be faster than with a monofilament tennis string and the comfort provided by the gut will not compensate for the frequency of breakage with this style of game.

Also, tennis players who are fans of high tensions or who do not wish to make adjustments to lower the tension of their setup will not be satisfied with a gut tennis string, which is more expressed at low tensions, from 17 to 23 Kilos Maximum, at the risk of seriously hampering its characteristic elasticity, its power and its resistance to breakage. 

Indeed, playing a gut tennis string implies going in the direction of its characteristics to get the most out of it and the best possible contribution to your tennis. A string so elastic and thick cannot be used for medium and high tensions or for a play with dominant spin.

 

Examples of professional players who play a gut tennis string:

Roger Federer (22.5 Kg Natural Gut Uprights / 26.5 Kg Luxilon Alu Power Rough Travers)

Novak Djokovic (23.5 Kg Natural Gut Uprights / 28 Kg Luxilon Alu Power Travers)

Andy Murray

Alexander Zverev

Grigor Dimitrov

Serena Williams (22 Kg Natural Gut Travers)

Emma Raducanu

Caroline Wozniacki (20 Kg Natural Gut Amounts)

If we look with a tennis specialist's eye at these profiles of players who still use gut tennis strings, we can say that these are not styles of play very marked by maximum spin, but rather profiles of more complete and versatile tennis, with covered strikes that are more impactful than a characteristic topspin, unlike playing styles such as Rafael Nadal, Dominic Thiem, Carlos Alcaraz, Coco Gauff, Jessica Pegula or even Garbine Muguruza, all in fullset monofilament tennis strings co-polyester.

We also note, for the few examples above where the tensions are detailed, that professional tennis players have a very large difference in tension between the tension of their gut tennis string and their monofilament tennis string, in order to optimize its performance and durability to the maximum (gap of more or less 4 Kilos with a monofilament tennis string, it's huge but necessary to use a gut tennis string). We also note that with professional tennis players like Emma Raducanu or Alexander Zverev, the gut tennis string is still used by young and full career profiles and is not exclusively played by previous generations.

TO WHOM TO ADVISE IT?

In general, the gut tennis string laid in full set can be recommended to all amateur and leisure level tennis players and of all ages who wish to put a high and regular tennis string budget at the service of their game, their sensations and in the prevention of arm injuries.

We can also strongly recommend the use of gut tennis strings very early in competition level juniors rather than a synthetic or multifilament gut tennis string in order to boost their sensations, their general power and gain a few hours of play before the break.  ;

Still for juniors at the competition level but in transition to monofilament, making a hybrid with a gut tennis string can be an excellent idea to protect the arm while increasing the quality of the tennis string used and getting juniors used to the use of tensions bass.

Similarly, seniors over 60 and any adult who is already a fan of a full set or hybrid gut tennis string are strongly recommended to stick with such a choice, always to protect the arm as well as possible without deprivation of sensations, but also to have a net boost of power and absorption of enemy strikes! The recommended adjustments of the hybrid tennis string with gut for the senior adult will more often be either the transition to natural gut in full set, or the gradual decrease in tension of the monofilament tennis string laid in hybrid with the gut tennis string.

For adult competitors and good club players of any age, with a complete style of play and/or looking for versatility and power and who do not rely exclusively on spin, we will always recommend trying at least once in his or her life as a player, the hybrid gut tennis string (with its current tennis string) to form an objective opinion of its contribution to your tennis, by following the following principles for an optimal test:

Place the gut tennis string in the crossbars of the hybrid for more versatility and comfort

Place the gut tennis string in the uprights (inverted hybrid) for more power 

Lower your usual tension for gut tennis strings by at least 3 kilos.

If you are already a user of multifilament or synthetic gut tennis strings in full set or hybrid tennis string, we can only recommend that you try to replace your current string once with a gut tennis string to form your own opinion, by lowering your usual blood pressure by 1 to 2 kilos.

If you want to play a gut tennis string but you don't have the budget, it is recommended to turn instead to a high-end multifilament tennis string a little cheaper than a synthetic gut tennis string....OR TRY OUR CHEAP TENNIS CORDAGE BOYAU THE GUT 😉🎾!

At UNI-CORD®, we have developed our own version of the gut tennis string with THE GUT 1.31, trying to offer you a cheap gut tennis string, a real challenge that we have taken up!

Our gut tennis strings are on average 25 to 30% cheaper than the gut tennis strings of historic tennis brands, with strictly identical production quality 

Cordage Tennis Pas Cher - Court de Tennis UNI-CORD

The Cheap Natural Gut Tennis String Is HERE! 

Babolat Tonic+

Klip Legend

Kirschbaum Touch Natural

UNI-CORD® offers only one low-cost "coated" natural gut type tennis string, of premium quality and worthy of the best gut tennis strings, in order to offer tennis players on a budget who wish to have better sensations and an inexpensive tennis string in natural gut at the price of €35.70 for a 12-meter set (Excluding Promotion!)

excellent value for money for an inexpensive, top-of-the-range tennis string.

The Coated Natural Gut Tennis String: The Only Evolution of the historic tennis string?

Historical string of tennis that has gone through centuries of practice where it was exclusive and still used to this day at a time when modern tennis is explosive and overflowing with power, the gut tennis string has however known very few evolutions in its own design, in particular insofar as this tennis string derives its raw materials from animal origin, there can be no significant technical or scientific changes.

 

Few changes therefore, except for the quality and the evolution of the various treatment agents which have greatly improved the resistance of the gut tennis strings, this product has always been able to remain almost the same over time, at a time when tennis changes are obvious! How to explain and justify the use of natural gut tennis strings and still recommend it to this day?

Over the years, where tennis has tended to gain exclusively in power, weight and spin of strikes, but also speed due to the general lightening and optimization of materials used for tennis racquets, without counting the democratization of the large 645cm2 (100in2) headsizes, it was necessary to try to strengthen the gut tennis string without distorting it for its followers among the best players in the world, manufacturers had to adapt between 1875 and today today!

While there are currently versions of colored natural gut or very thin gauge versions on the tennis string market, the process of wrapping the gut tennis string with a synthetic coating remains the small technical development that has made it possible to adapt to the needs of modern tennis.

In fact, wrapping the gut tennis string consists of applying a more or less thin synthetic coating depending on the manufacturing quality of the natural gut.

When a gut tennis string has a cover, it is a "Coated" type gut tennis string or Coated Natural Gut in English.

(Coat: the mantle, which designates the layer / the envelope of the gut tennis string)

When a gut tennis string does not have a cover, it is a 100% natural "Uncoated" or Original type gut tennis string.

 

Originally, the gut tennis string did not have an envelope! The addition of a resin or polyurethane cover to the surface of the gut tennis string is the major technical development in the production of this string. Applying a coating to a gut tennis string has many advantages:

The casing of the gut tennis string not only helps to protect the filaments, their braiding and the core of the string when laying the rope on the tennis racketbut also in the game on every keystroke to reinforce its structure and protect those same elements before they are damaged by natural wear and hours of high-intensity play. 

The casing of the gut tennis string therefore preserves the internal structure of the entire string, but also increases its durability, its tension resistance and its resistance to breakage.

It is a major advance and adapted to modern tennis which allows the gut tennis string to still exist today and to still be played on professional circuits at the highest level in the world.

At UNI-CORD®, the gut tennis string that we have developed, THE GUT, is also a coated type gut tennis string, it has a thin polyurethane cover (material found on soft type monofilament tennis strings ) which protects it during installation by the stringer but also reinforces this gut tennis string without distorting it!

Precautions and Recommendations with a Gut Tennis String

The gut tennis string is a living product of animal origin!

In this sense, it is a naturally perishable product in itself, despite the efforts of the manufacturers to treat this tennis string with the greatest care to increase its durability.

However, some precautions should be taken when buying, storing, stringing, and playing gut, coated or original tennis strings.

You have made the choice or wish to switch to a gut tennis string:We tell you everything here!

Stringer's Advice: 

 

The gut tennis string has an expiry date: Yes !You cannot keep your gut tennis string in its pouch (even if it is insulated and airtight) indefinitely.. Moreover, if you look in more detail at your cover or the manufacturer's website or if you ask your sales consultant in a specialized tennis store, you will be told that the lifespan of a tennis string casing in its pouch without having been placed or played is counted and will not exceed a maximum of 1 year before the product and its properties deteriorate. If this natural degradation of the gut tennis string could not be noticed with the naked eye, know that during the installation with the stringing machine or immediately in game this one will be stiffened and will lose greatly in elasticity and comfort. A gut tennis string worn over time will therefore tend to dry out a lot, and will therefore be highly susceptible to stiffening, yellowing, cracking, and peeling easily and quickly.

So don't buy your gut tennis string sets too early and don't stock up too much!

Get into the habit of ordering or buying it just a few days before the end of the tennis string on your racket.

Preferably, and this is one of the best advice we can give you: If possible, string your gut tennis string the same day or the days following the purchase or receipt of your string. By adopting this habit, you avoid letting your gut tennis string deteriorate over time without even having played it!

If you open a set of 12 meter gut tennis strings and only use 6 meters of gut tennis string per racket: String your tennis rackets two by two! Yes one more reflex to adopt moreover but which will allow you not to let your second set of 6 meters deteriorate quickly in the ambient air after opening the pocket to string a single racket, reason rather in pairs.

Nor can you keep a natural gut tennis string on your racket for long (with or without hours of play), for the same reasons mentioned above, especially since its direct exposure to heat, humidity and the light will cause it to lose its yield very quickly within a few days.

 

The gut tennis string should be stored with care: It is a very fragile tennis string which, placed on a racket or not, enclosed or not in its pouch, is sensitive to all external elements! Get into the habit of always keeping your garnishes away from heat and light (preferably in a cellar if possible or even a wine cellar, otherwise in a dark and cool room).

 

To keep your tennis racquets with a gut tennis string placed on them, always protect your racquets and the string from the ambient air and dust before and after your tennis session by storing them hermetically with a rubber band in their plastic bag (the plastic bags that you are given when you buy or deliver your racquets: absolutely keep them! These are the ones that pro players remove in the middle of a match when they change racquets)

Always store your tennis rackets, if possible, in the insulated part of your tennis bag (thermobag) and close this pocket to protect the gut tennis string from the sun or moisture

Laying the gut tennis string is an art: Entrust the installation of the gut tennis string to a professional and experienced stringer! Indeed, the method for best laying a gut tennis string and a monofilament or multifilament tennis string is completely different and requires much more time and attention!

If you string your gut tennis string yourself, absolutely follow our advice to avoid weakening it during installation, at the risk of losing all its qualities before playing it: 

- Unroll the gut tennis string slowly and pay attention to the knot that forms while rolling it up!

- Extend and pull the gut tennis string to its full length by hand

- Gently cut the gut tennis string with a bevel!

- Slow down all your poses (passing the rope through the eyelets, uprights and through the racket; blocking the rope in the tensioner; tensioning; etc.)

- If you have an electronic machine, slow down the tensioner speed to the lowest!

- Block the top of the stringing machine if possible before each tension of the string

- Do not overtighten your tension clamps: strong pressure breaks the fibres, weakens and bleaches the rope!

- Do not apply a large overvoltage to your knots (1.5 Kilo Maximum)

- Do not forcefully pull the finishing knots / Make double knots with two loops

- Do not force the passage of the gut tennis string through an eyelet, use the awl (the punch) to enlarge it

- Do not rub the crossing with the gut tennis string, leave some slack

- Perform (optional) a pre-stretch of 10% maximum

- If the gut tennis string is placed in the uprights, place power-pads* (*Leather wedges which round off the angles of tension of the gut string) on the eyelets at the heart of the racket only

OR ENTRUST US WITH THE INSTALLATION OF YOUR TENNIS BOYAU STRING 🎾

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