Types of tennis strings

Strings look alike on the shelf, but inside they are very different. How a string feels comes mostly from what it is made of and how it is built: one solid strand, hundreds of thin fibres, or a natural fibre? This guide goes through the types one by one. If you just want a quick pick, the short recommendations in the string selection guide are enough.

Natural gut

Usually made from thin ribbons taken from the outer layer of cow intestine, twisted together and coated. It was tennis's first string and is still regarded as the softest and liveliest one.

• Plus: It holds tension better than any other string and still feels like the first day weeks later. It is the easiest string on the arm.
• Minus: The most expensive string, and sensitive to moisture and rain. It wears quickly under heavy spin.
• For: Players who want comfort and feel and can afford it, and players with arm pain.

Multifilament

Hundreds, sometimes thousands, of thin synthetic fibres bound with resin and finished with a protective coating. The aim is to get close to natural gut's softness at a lower price.

• Plus: Soft, powerful and arm-friendly. It feels like it "holds" the ball.
• Minus: Over time the coating wears and the fibres fray. That is normal but means a break is coming. It breaks quickly for very hard or spin-heavy hitters.
• For: Beginners and intermediates, and anyone who wants to look after their arm.

Synthetic gut

Despite the name, it contains no natural fibre. It is a single nylon core with one or two layers of thin wraps. Most factory-strung rackets come with this kind of string.

• Plus: Cheap and average at everything. A good default if you are new to stringing.
• Minus: It holds tension less well than multifilament and the feel is ordinary.
• For: First strings, occasional players, players on a budget.

Polyester (monofilament)

One solid strand. Most polyesters sold today are "co-polyesters" with additives that lower the stiffness or change the feel. The cross-section can be round, shaped or twisted; how shape affects spin is in the strings and spin guide.

• Plus: Durable and hard to break. For fast swingers it adds control and makes spin easier.
• Minus: The hardest type on the arm. It loses tension quickly and goes "dead" before it breaks: after a few weeks it starts to feel hard and lifeless.
• For: Fast, full swingers who break strings often and have no arm pain.

Polyesters differ a lot among themselves. The ones sold as "soft" can feel as gentle as a stiff synthetic gut. If your arm is sensitive, see the arm-friendly strings guide.

Aramid (Kevlar)

A very stiff fibre that almost never breaks. It is not used on its own for a whole racket; it is too hard on the arm. Players who break strings every week use it in a hybrid, usually in the mains.

Hybrids: combining two types

In a hybrid the mains (vertical) and crosses (horizontal) are different strings. The most common setup is polyester mains with multifilament or natural gut crosses: the control and life of polyester with the comfort of a soft string. Some brands sell ready-made hybrid sets. More in the string selection guide.

Which type suits you?

Set or reel?

Strings are sold as a single-racket set (about 12 m) or as a reel (usually 200 m). A 200 m reel strings about 16 rackets and works out cheaper per stringing. If you restring a few times a year, a set is enough; if you restring often or have several rackets, a reel makes more sense.