Free Fly Men's Seawool Flannel Shirt Review: Sustainable Layering That Actually Works

I tested the Free Fly Men's Seawool Flannel Shirt and found a lightweight, sustainable flannel perfect for layering. Here's my first impressions of this eco-friendly shirt made from recycled materials.
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I’ve owned my fair share of flannel shirts over the years, from the heavy, sturdy work shirts to the lightweight weekend options. When I got my hands on the Free Fly Men’s Seawool Flannel Shirt, I was curious to see how their sustainable approach would stack up against traditional flannels.
Here’s my first impressions after testing this eco-friendly flannel.
A different kind of flannel
The first thing I noticed about this flannel is how lightweight it feels compared to the heavy, sturdy flannels I’ve owned in the past. This isn’t your typical thick, work-ready flannel that could double as a blanket. Instead, it’s designed as a proper layering piece.

What makes this work so well is the brushed twill construction. It has that classic flannel texture and feel, but without the bulk. This makes it perfect for wearing under a jacket or over a T-shirt, which is exactly how I tend to layer my flannels anyway.
The fit that works for me
I’m a true-to-size Medium when it comes to Free Fly, and this flannel fits exactly as expected. The relaxed cut through the body gives me plenty of room to move, and there’s ample space in the armpits and shoulders where I need it most.
The sleeve length is spot-on for my frame, and I appreciate that I can cuff and roll up the sleeves as part of my preferred style. I tend to button up my flannels rather than wearing them open, and this one works perfectly with jeans or canvas pants for weekend outings or hiking trips.
The sustainability factor
Here’s what really impressed me about this shirt: the sustainability story. The Seawool fabric is made from upcycled oyster shells and recycled plastic bottles, but you’d never know it from the feel. If I hadn’t been told about the recycled materials, I would have thought this was a soft cotton-wool blend.

The 57% cotton, 40% recycled Seawool polyester, and 3% spandex blend creates a fabric that’s thermo-regulating, anti-odor, and quick-dry. These are the same performance benefits you get from Free Fly’s bamboo styles, but in a classic flannel package.
A note on materials
I should mention that if you have sensitive skin and worry about the plastic component in recycled materials, this might not be the right choice for you. While the fabric feels incredibly soft and comfortable to me, the recycled plastic bottle content could be a concern for those with skin sensitivities.

For me, the environmental benefits outweigh any concerns, especially knowing that all those recycled plastic bottles never get the chance to end up in our oceans. It’s a win-win for performance and sustainability.
Perfect for travel and everyday wear
The lightweight construction makes this flannel ideal for travel. It packs down small, dries quickly, and provides just the right amount of warmth for layering. The left chest pocket is perfect for stashing sunglasses, and the classic styling works whether you’re exploring a new city or heading out for a weekend adventure.
The 177 GSM fabric weight hits that sweet spot between lightweight and substantial enough to feel like a real flannel. It’s not flimsy, but it’s not heavy either. This makes it versatile for different weather conditions and activities.
What I’d change
If I had to nitpick, I’d love to see this in more color options. The classic flannel patterns are great, but Free Fly’s sustainable approach would work well with some more modern colorways too.
Bottom line
The Free Fly Men’s Seawool Flannel Shirt delivers on its promise of sustainable performance. It’s lightweight enough for layering, comfortable enough for all-day wear, and sustainable enough to feel good about the purchase. The fit is spot-on, and the fabric feels premium despite being made from recycled materials.
This is exactly the kind of flannel I want in my travel wardrobe: functional, sustainable, and built to last.
Next steps
Ready to try the Free Fly Men’s Seawool Flannel Shirt? Check it out here.
Related reviews:
- Free Fly Brand Page - Explore all Free Fly sustainable apparel
- Best Travel Pants for Men - Complete travel wardrobe essentials
- Best Travel Shorts for Men - More travel apparel recommendations
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