• USRSA String Rankings 1998
• Kinds of Strings
• String tension
• What can I do to help reduce vibration?
• How often should I restring my racket?
• Where can I restring my racket?
• 18 Basic Facts about Strings

•   USRSA String Rankings 1998
  Every August, 1,000 USRSA members - professional stringers  are asked which string they like in  terms of playability, durability, and overall performance. Here are the results of the 1998 survey:

• Kinds of Strings
  Basically there are three kinds of strings you can get:

• Nylon,
• Gut, and
• Synthetic Gut.  
  
  Nylon is cheap and durable, but it is not overly resilient and tends to lose tension before it snaps.
  Gut is the choice of many pros, but it is rather expensive and generally not recommended unless you can afford to buy in bulk and have your own stringing machine. Gut strings are resilient, hold tension better, and players like the feel better.   However, humidity affects the strings and cause them to degrade.    Gut doesn't last as long as nylon.
  
  The compromise is synthetic strings.   Basically, gut is made by long thin strands of cow or sheep gut, and it is twisted together in much the same way twine or string is made.  Synthetic gut does the same thing with nylon strings to achieve the same effect.   They cost more than nylon but less than real gut.    They play and hold tension better than nylon.

There are three basic types of synthetic strings: monofilaments, multifilaments, and aramids.

• Monofilaments are simple, safe, and consistent. Composed of a single, solid core string encased in a thin outer cover, monofilaments are good all-around performers. They hold tension well and offer a pleasing mix of durability and playability. Sixty-one percent of the strings that made the 1998 U.S. Racquet Stringer Association (USRSA) rankings were monofilaments.

• Multifilaments are manufactured from hundreds, often thousands, of individual fibers that are woven together to create a uniform piece of string, which is encased in a protective, feel-enhancing coating. In some instances, a manufacturer will put on a second layer of coating, giving the string an exceptionally soft feel.
  What are the advantages of multifilaments? For one thing, they're very resilient and bend a lot on impact. This generates a trampoline effect when the ball is hit, giving you more power.
  The downside to multifilaments is that they're generally not as durable as monofilaments, and tend to lose their tension more quickly.

• Aramids are made of strong materials like Kevlar and Technora, and are the most durable strings on the market. Because of their inherent stiffness, aramids tend not to be resilient and don't deliver much feel or power, though they do hold their tension exceptionally well.
  Most aramids are strung in the mains (the strings that go up and down, and which are more likely to break), with a monofilament string in the crosses for extra feel. This combination creates what's known as a 'hybrid.' For chronic string-breakers, hybrids are a good value.

So-called "topspin" strings are mostly gimmicky and should probably be avoided.  These are rough surfaced strings designed to grab the ball better. The feel or durability of the strings are not necessarily improved.

Cost of strings range from about $10-$15 (US) for nylon to $12-$30 for synthetic gut to $30-$50 for gut strings.  Strings can be purchased in large reels for stringing at home for less.

String Gauges (String Thicknesses)

Strings come in various thicknesses, called "gauges." You have 15, 15L, 16, 16L, and 17.  Larger numbers mean thinner strings.    "L" means light and can be thought of as half as size (so 15L can be considered 15 1/2). Thick strings have less resilience and feel than thin strings but last longer.

• String tension

Note: 1 pound (lb.) = 0.448 kg * 9.8 m/s^2 = 4.39 Newtons

String tension is usually measured in pounds (in the US).    Recommended string tensions have varied with the times but these days usually run in the range of the mid 60's (pounds) for oversize and high 50's to low 60's for mid-overs.

How do you choose a tension?   If you're unsure, choose a tension that is halfway between the manufacturer's ranges.  You can then adjust up or down until you find the tension most suitable for you.  Exceeding the limits of manufacturer's recommended string tensions might void the racquet warranty (check with the racquet company if you have questions), but most racquets can withstand a great range of tensions before damage sets in.  Higher tensions will probably cause a little more damage than lower tensions.

Basically, higher tensions decrease the size of the sweetspot and reduce the power (thus increasing control a bit).  The higher the tension, the more boardlike the feel.  Some people like this.  Desired tension is pretty much a matter of personal taste, and as you improve the level of your game, you are apt to notice small fluctuations in string tensions.

Also note that the same string tension will have a different "feel" for different racquets.

• What can I do to help reduce vibration?
  Ask for strings that are softer and more flexible and/or reduce your string tension or use vibration dampeners.

• How often should I restring my racket?

Restringing throughout the year should occur as frequently as you play tennis each week, or at least once a year; for example, if you play tennis three times a week, you should restring your racket three times a year. Remember that high string tension provides less power and more control; and low string tension provides more power and less control. To custom fit your racket with the ideal replacement string and tension, refer to the guide on the throat of the racket.

• Where can I restring my racket?

Proper stringing is very important to your racket's playability. Stringing should only be done by an experienced stringer, preferably a Certified Racket Technician (CRT).

• 18 Basic Facts about Strings

1. Lower string tensions generate more power (providing string movement does not occur).

2. Higher string tensions generate more ball control (for experienced players).

3. A longer string length (or string plane area) produces more power.

4. Decreased string density (fewer strings) generates more power.

5. Thinner string generates more power (Wilson's research for their Sweetspot string disputes this theory).

6. More elastic strings generate more power (generally, what will produce more power will also absorb more shock load at impact).

7. Softer strings, or strings with a softer coating, tend to vibrate less.

8. Thinner strings tend to produce more spin  by biting the ball more.

9. Decreased string density (fewer strings) generates more spin.

10. Multifilament strings are more elastic than solid core strings.

11. Longer strings on a string bed move more hence break easier (see larger frames from above).

12. Solid core strings are more durable than multifilament strings with kevlar string technology being         the most durable.

13. Kevlar strings are the stiffest and least flexible.

14. Multifilament strings play better than solid core strings.

15. Multifilament strings lose tension more quickly than strings with a center core.

16. Textured strings tend to produce more spin.

17. Gut strings hold tension the best.

18. Gut strings are the most fragile strings comparing to other similar gauged strings.