Co-poly vs multi.
Pick a side.

The short version

Multifilament is soft, powerful, and arm-friendly. Co-poly is stiff, controllable, and built to bite the ball. If you swing hard and want the ball to do something on the way down, you want co-poly. If you play twice a month and just want the ball back, stay on multi.

Everything below is the long version.

What multifilament actually is

Multifilament strings are hundreds — sometimes thousands — of thin nylon or polyester microfibers bundled and wrapped inside a coating. The construction mimics natural gut: soft, elastic, forgiving. When you hit the ball, the whole bundle deforms, launches, and springs back.

That's what makes multi feel plush. It's also what caps its ceiling. A string that deforms easily gives the ball its own energy back, which means power without the control layer on top. On a hard swing, the ball leaves the strings faster than you can aim it.

What co-poly actually is

Co-poly is a single monofilament — one stiff polyester strand — with additives (silicone, polyamides, other polymers) engineered into the extrusion. That stiffness is a feature, not a bug. On contact, the string bed barely deforms; instead, the mains slide sideways under the ball, bite in, and snap back into place. That snapback is where topspin comes from.

You feel co-poly less. It gives you less free power. In exchange, it gives you a ball that dips inside the baseline when you swing out on it.

Side by side

Who should be on multi

• You play once a week or less and want the ball to come back with no effort.
• You've had tennis elbow, wrist trouble, or shoulder issues that flare up on stiff setups.
• You're a junior still developing swing speed, or a senior who's dialed the swing back on purpose.
• You play social doubles and rallies more than points.

Who should be on co-poly

• You swing fast and full. Your flat drives are landing three feet long on multi.
• You want your topspin to actually kick, not just arc.
• You're breaking multifilament in under 10 hours of play.
• You play matches, not just hit. You care where the ball lands.

The switch: what to expect

First session on co-poly, everything will feel short. Your usual swing will produce a shorter ball. That's the point — the string isn't adding power for you anymore. Trust it and swing bigger. Within a few hits, the ball starts diving inside the baseline instead of sailing over it.

Second thing: string it lower than your multi tension. If you played multi at 55, try co-poly around 50. If your arm is sensitive, drop a couple more pounds. Higher tensions on poly feel stiffer; lower tensions inside the range feel livelier and, for most players, more comfortable. If a setup causes pain, stop playing it.

Third: restring on a schedule. Poly loses tension fast and usually goes dead before it breaks. Rule of thumb — restring as many times per year as you play per week. Play three times a week, aim for three restrings a year.

The hybrid option

Poly mains, multi crosses. The mains do the spin work — they're what slides and snaps back on the ball. The crosses just hold the mains in place, so a softer multi cross can soften the overall feel without giving up bite. Try SNAP Spin in the mains with your favorite multi in the crosses.

It's a popular setup for players who want poly's bite without the stiffness of a full-poly bed.

Where SNAP fits

Two co-poly strings. No gimmicks. No tour endorsements. Both string at the low end of the poly range and both hold up in match play.

SNAP Spin

Shaped co-poly for heavy topspin baseliners. Make the ball misbehave.

SNAP Control

Hexagonal co-poly for flat first-strike players. Aim smaller. Swing bigger.

Duel Pack

One set of each. Let the court decide.

Not sure which SNAP is you?

The stringing guide has a six-question quiz that spits out the right string and tension. Or email us — same voice on the other end.

String it. Send it.