Exclusive Story Behind the ReString x Valldoreix Collaboration

This article is part of our limited edition ReString x Valldoreix Collaboration.

Sometimes the best partnerships start with a simple Instagram message.

That's exactly what happened when Julio from Valldoreix connected with us last year.

What began as a casual conversation between two brands turned into a year-long collaboration that brought together performance engineering and thoughtful design.

In this article, I'll share how both brands approached the design process, and how every detail from the hoodie fit to the packaging color came together to create something special.

It Started in Washington DC

Julio from Valldoreix was scrolling through Instagram last fall when he saw my post of me playing tennis. The courts looked familiar, so he sent me a message asking if I was playing at Georgetown courts in DC.

I said yes and quickly discovered that Julio had studied at Georgetown. The DC connection immediately clicked. He had spent his college years there while ReString operates from the same city.

The initial conversation flowed naturally. I asked Julio if he wanted to hit the courts together next time he was in town. No agenda, just two people who love tennis and respect what the other is building.

March 2025 arrived and the meetup happened. Julio and I played for about an hour and a half on Georgetown's courts. The aesthetic was perfect. Green-on-green courts surrounded by trees in full spring bloom created a private, almost secluded atmosphere.

Before we wrapped up, I handed Julio some ReString samples.

From Samples to Collaboration

Julio took the strings for a spin and really liked what he felt. The performance impressed him enough that conversations naturally shifted toward doing something together.

Both ReString and Valldoreix share a belief that tennis needs fresh perspectives.

ReString approaches it through string technology and sustainable projects. Valldoreix does it through apparel design and storytelling.

The alignment was clear, so we moved forward with defining what each brand would bring to the table. ReString would develop a string. Valldoreix would create an apparel piece.

The collaboration took a year in the making. That timeline included design iterations, product development, and all the back-and-forth needed to get every detail right.

Designing the Collaboration

The “SLAP” Hoodie

The "SLAP" Hoodie design process involved multiple rounds of iteration and discussion. Julio led this part of the collaboration, bringing his creative vision to guide the process.

We chose an oversized fit deliberately. A traditional-sized hoodie would have been the safer choice, but oversized broke from convention and added to the modern aesthetic both brands wanted.

Then came the specifics. Should the hoodie be a solid color or have a washed finish? Should the collaboration logo sit on the front or the back? Should text appear on the sleeves or stay minimal?

Each choice reflected both brands' philosophies merging into one piece.

ReString brings clean, performance-driven design. Valldoreix brings thought-provoking concepts. The hoodie needed to honor both approaches while feeling cohesive.

The back-and-forth process took time but resulted in something both teams felt genuinely excited about.

The “SLAP” String

The "SLAP" String side came together more quickly because Nick and I had been testing variations for years. We constantly experiment with different shapes, colors, and formulas, so when the collaboration opportunity arrived, we already knew what would work.

The “SLAP” String builds on Zero technology. The hexagonal shape delivers maximum bite on the ball while the formulation provides raw power and spin. We went with 17G because it's the most popular size among players.

The midnight black colorway sets The “SLAP” String visually apart from ReString's existing lineup. Zero comes in blue, Sync in gray, and Vivo in aqua.

The name “SLAP” also follows ReString's four-letter convention. Zero, Sync, Vivo, and “SLAP”. All four letters, all distinctive, all connected to how the string performs or feels.

Packaging needed to match the special nature of this release. We typically use white sleeves with small corner design elements. For The “SLAP” String, we went all black.

The dramatic shift in visual identity makes the limited edition nature immediately obvious. When you see that black sleeve, you know you're looking at something different.

The packaging departure also shows how both brands approached this collaboration. Neither of us wanted to play it safe. We pushed boundaries in our own ways and the all-black sleeve reflects that willingness to break from established patterns.

The Logo

Julio deserves major credit for the collaboration logo. His creative vision brought the concept together in a way that felt perfect from the first draft.

Valldoreix's brand icon shows an illustration in a serving motion. The detail that makes it distinctive? There's no tennis ball in the image.

ReString's icon features a circular element in the center. That circle resembles a tennis ball.

The collaboration logo merges both icons. The serving motion from Valldoreix meets the circular element from ReString, and suddenly you have a complete image.

When Nick and I first saw the logo, the reaction was immediate. This felt like what happens when major brands collaborate like LOEWE × On or ASICS x A.P.C.

The emotional impact of seeing the final design reinforced that this collaboration was something special. Not just two brands slapping logos on products, but a genuine creative partnership.

Conclusion

In some ways, this collaboration mirrors how ReString itself started. Two friends connected by a shared love of tennis and decided to build something unique.

If you want to experience what happens when two independent brands push each other to create something fresh, this collaboration delivers exactly that.

Get the ReString x Valldoreix "SLAP" String and "SLAP" Hoodie while stocks last.

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.