String Project Armour, monofilament tennis string
String Project Armour is a co-polyester competition monofilament tennis string (Soft Polyester + High-Density Polyester HDC), engineered to deliver an evolution in ball feel and control.
- Co-Polyester Monofilament
- Gauges 1.25 · 1.32 mm
- Arm Friendly®
- Tension 18–22 kg
Playing profile
String Project Armour delivers competition-level control (8.5/10), letting you place every shot with precision and confidence. Spin (9/10) is generated naturally thanks to the excellent snap-back, while power (7.5/10) is contained and calibrated, ideal for those who prefer to build the point with tactical intelligence rather than brute force.
- Spin9/10
- Control8.5/10
- Tension8.5/10
- Comfort8/10
- Resilience8/10
- Power7.5/10
Ratings and technical specifications measured in the laboratory by Pro-t-one (Eng. G. Medri) — laboratory test report (PDF).
Absolute control and superior feel on court
On court, Armour stands out for its versatility. In a full-bed setup it offers a solid impact that instils confidence in every shot. In a hybrid setup, its smooth texture and responsiveness generate unusual spin, with a dynamic response to the ball. Power is manageable, allowing you to meter force with precision. Despite its robustness, Armour offers remarkable comfort, absorbing vibrations and protecting the arm.
Competition feel and control
Armour offers competition-level control (8.5/10), with direct, communicative impact feedback. Its impact consistency lets you build the point with tactical precision.
- Direct impact feedback
- Excellent shot consistency
- Precise directionality
- Tactical point construction
Surprising spin generation
With 9/10 spin, Armour generates effective, natural rotation thanks to its clean, predictable snap-back. The smooth surface and Low Friction treatments amplify the string's return to position.
- Natural, consistent 9/10 spin
- Clean, predictable snap-back
- Effective rotation on every shot
- Heavy, controlled topspin
Competition composition and Arm Friendly®
String Project Armour is made of co-polyester, a composition that balances Soft Polyester and High-Density Polyester (HDC). Soft Polyester ensures softness and vibration absorption for its Arm Friendly® certification, while High-Density Polyester provides structural stiffness, impact consistency and long-term durability. The smooth surface of the round cross-section contributes to a clean, predictable snap-back.
The manufacturing processes
Pre-Stretch
Thanks to the "pre-stretch" of the core, the entire string minimises tension loss while at the same time allowing a lower stringing tension.
Double Heating
The "heat treatments" remove internal stresses and even out any irregularities in the string. They also make the strings more flexible and elastic.
Liquid Wax
The string is finished with a layer of wax. This treatment significantly extends its lifespan by reducing wear and making stringing easier.
Low Friction
Reducing the string's friction delivers reduced string movement, greater spin potential thanks to improved snap-back, and a longer lifespan.
Technical data sheet
| Feature | Value |
|---|---|
| Type | Co-Polyester Monofilament (Soft Polyester + HDC) |
| Cross-section | Round (smooth) |
| Gauges | 1.25 mm · 1.32 mm |
| Dynamic stiffness | ~230 g/mm |
| Manufacturing processes | Pre-Stretch, Double Heating, Liquid Wax, Low Friction |
| Recommended tension | 18–22 kg |
The right string if you see yourself here
Control-oriented competitors
Those who build the point with tactical intelligence and want a string that returns direct feel and precise directionality on every shot.
Those seeking consistency
Those who want a string with solid, predictable impact that keeps its properties over time thanks to 8.5/10 tension maintenance and 8/10 resilience.
Those who want spin without giving up control
Those who generate spin as an integral part of their game but need rotation to be controlled, precise and repeatable.