Guides

How to Hybrid Two Polyester Tennis Strings

March 1, 2026 Juan

A polyester-polyester hybrid places two different polyester strings in one racket to fine-tune performance beyond what a single string can deliver.

This setup is used on the pro tour by players like Casper Ruud, Lorenzo Musetti, and WTA player Cristina Bucsa who competes with Zero in the mains and Sync in the crosses.

However, you don't need to be on the pro tour to benefit from this approach. At every level, a polyester hybrid gives you the customizability you need to play your best tennis.

This article covers how to choose which polyester string goes in your mains and crosses, how to set tension and gauge, and what the best polyester hybrid setups are.

Choose Your Mains and Crosses

Your mains (vertical strings) account for roughly 70% of how your racket feels and performs. Whatever characteristic you want the most of should go in the mains.

Your crosses (horizontal strings) act as a modifier. They influence how freely the mains can move and how the overall stringbed responds at contact.

Chart showing the difference in play characteristics of mains strings vs cross strings in tennis.

An expert tip for choosing your mains and crosses is to pair a shaped string like Zero in the mains with a round, smooth string like Sync in the crosses.

Since your mains thrust upward through the ball on most groundstrokes, they are primarily responsible for generating spin. A shaped string in this position grips the ball and maximizes bite.

A smooth, slick cross then reduces friction and lets the mains slide and snap back freely for even more spin. You can also use the crosses to add comfort by choosing something softer, or to enhance pocketing and feel.

Pacing shaped strings in both the mains and crosses can cause them to saw into each other. This can lock the stringbed, accelerate notching, and cause your strings to go "dead" much quicker than they should.

Set Up Your Tension and Gauge

Once you've chosen your strings, the next step is getting the tension right.

The best way to set up the tension in a hybrid setup is to string your mains 2-3 lbs tighter than your crosses. This differential increases string movement in the stringbed and encourages more snapback, which translates to better spin potential and a more responsive feel.

Gauge offers another layer of customization in your hybrid setup. If you want to take your tuning further, consider using a different gauge in your mains and crosses.

A thicker main string (15G or 16G) adds durability and control, while a thinner cross string (17G or 18G) enhances string movement and feel.

This is particularly useful for frequent string breakers, since moving up a gauge in the mains before raising tension can improve string longevity without sacrificing the playability benefits of your setup.

Best Polyester-Polyester Hybrid Setups

Zero and Sync

Zero mains and Sync crosses is our most popular polyester hybrid setup. This combination offers explosive power and heavy spin with added control and precision.

Zero mains deliver maximum bite and snapback for aggressive spin generation. Sync crosses moderate the power and introduce directional accuracy, while still offering excellent snapback through its Signature Snapback coating.

This is a versatile setup that suits a wide range of players and playing styles. It's also the same hybrid that WTA pro Cristina Bucsa trusts on tour.

Vivo and Sync

Vivo mains and Sync crosses combines control and spin with high-level precision.

Vivo mains establish a firm, direct response with excellent control and bite on the ball. Sync crosses add smoother string interaction through its Signature Snapback coating, bringing more feel to the overall setup.

This combination appeals to players who value Vivo's consistency and crisp feedback but want a touch more feel from the stringbed.

We do not recommend reversing this setup with Sync in the mains and Vivo in the crosses, since it's generally better to have the shaped string in the mains and the slippery round string in the crosses.

Conclusion

To hybrid two polyester tennis strings, place the string with the characteristics you want the most of in your mains, and a complementary string in your crosses.

As a general rule, a shaped string in the mains paired with a round, smooth string in the crosses gives you the best combination of ball bite and string movement.

We recommend stringing your mains 2-3 lbs tighter than your crosses and using a thicker gauge in the mains if you break strings frequently and want more durability.

When experimenting, change one variable at a time and play at least a few sessions before judging, as polyester needs time to settle.

ReString's Half Set Custom Box provides 16 half sets of Zero, Sync, and Vivo for players looking to experiment with different hybrid combinations.

About the Author: Juan is the co-founder of ReString. He was born in Argentina, raised in Japan, and moved to the US to pursue college tennis. He now plays as an ATP & WTA hitting partner.