Inside Polartec® Alpha™ with Wool: A Conversation with Ramesh Kesh

For AW26, Purple Mountain Observatory worked with Polartec® Alpha™ Wool, a new evolution of the Alpha active insulation platform that combines its open, breathable construction with the natural moisture-management properties and tactile feel of wool.

You can view the product here

To understand more about the development of the fabric, how it performs, and where Polartec sees the future of technical textiles heading, we spoke with Ramesh Kesh, Senior Vice President for Innovation at Milliken & Company and Business Manager at Polartec.

01. Polartec has been at the forefront of performance textile innovation for decades. How has your approach to developing new materials evolved as the demands of outdoor athletes and consumers have changed?

The starting point is still the same: understand what the wearer needs, then build the material around that.

What has changed is the idea of performance. It’s not just about warmth or breathability in isolation anymore — it’s about how a fabric performs as conditions and activity levels change. We’re designing more for those transitions, so people can stay comfortable without constantly adding or removing layers.

02. What was the original idea behind developing Polartec® Alpha™ with wool, and what did you set out to achieve that existing insulation technologies couldn’t?

Alpha was always about active insulation — keeping warmth while still allowing air and moisture vapor to move.

With Alpha with wool, we wanted to build on that by bringing in the natural moisture-handling properties and feel of wool. The Alpha structure still does the work in terms of airflow and insulation, but wool adds another layer of comfort as temperature and humidity change.

03. One of the things that drew us to Alpha™ with wool was the combination of natural fibers and active insulation. What does wool bring to the Alpha construction, and how does it change the material’s performance characteristics?

Wool interacts with moisture differently from a synthetic fiber. It can absorb moisture vapor within the fiber itself, which helps smooth out changes in humidity close to the body.

In Alpha’s open construction, that sits alongside the fabric’s airflow and insulation. It also changes the hand feel, giving the fabric more softness and texture.

04. At PMO, we’re interested in creating products that work in the city as well as more demanding outdoor conditions. How do you see Alpha™ with wool supporting this approach to product design, particularly when it comes to temperature regulation and versatility?

That versatility is one of its strengths.

The open structure gives you warmth without completely shutting down airflow, and the wool adds comfort as moisture levels change. Worn on its own, it breathes very freely. Put it under a shell and it becomes part of a much warmer system.

That makes it useful for garments that need to work across different environments rather than one very specific use case.

05. What were the biggest technical challenges in combining wool with Alpha’s existing construction, and how did you overcome them?

The challenge was bringing wool into the construction without losing the openness and loft that make Alpha work.

Wool and synthetics behave differently in production and over time, so a lot of the development came down to getting the fiber mix, yarn construction, knit structure and finishing right.

The goal was to keep the airflow and insulation while making sure the fabric still had the durability and stability it needed.

06. We’re seeing an increasing interest in natural fibers within technical outdoor clothing. How do you see the relationship between natural and synthetic materials evolving, and what role will wool play in the next generation of performance fabrics?

We don’t really see it as natural versus synthetic. It’s more about using each material where it makes sense.

Wool brings moisture-vapor absorption and a particular feel. Synthetics can bring strength, stability and lower moisture uptake. The interesting part is how those properties are combined within the fabric.

Alpha with wool is a good example of that — using wool for what it does well inside a very engineered insulation structure.

07. What’s next for Polartec? Are there any emerging technologies or material developments you’re particularly excited about?

There’s a lot happening across insulation, weather protection and moisture management.

We’re working on insulation that can deliver more warmth for less weight, while still keeping the airflow that matters during movement. We also have new hemp and polypropylene fleece developments coming in 2027.

On the weather protection side, AIRCORE™ is part of our work around balancing protection with controlled air permeability, and we’re continuing to develop Power Dry™ and Delta™ for moisture management.

We’re also looking closely at manufacturing and material sourcing — from carbon-capture-derived inputs to more efficient dyeing processes.

The direction is really about getting more performance out of the material, while being more considered about how it’s made.