Finally, an N1 Jacket You Can Wear All Year Round

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Iron Heart’s Insanely Popular Lightweight N1 Gets a New Olive Update for FW26

The N1 deck jacket has been a favourite in raw denim circles for years, but its appeal is no longer limited to heritage menswear. Finding enough cold days to wear a traditional alpaca-lined version is another matter.

I’ve been part of the N1-wave myself. I got my first one from Iron Heart in 2019, and the second in 2024—both the classic alpaca-lined versions. Before that, I’d been eyeing the style for years (and even, briefly, had one from Pike Brothers).

Iron Heart nails the mix of build, shape, and attitude. It’s one of those jackets that just makes sense the second you put it on.

The only catch is that it’s warm. Really warm.

The Problem With the Classic N1

Working at Brund, Copenhagen’s Iron Heart retailer, I’ve seen firsthand how fast the winter N1s move. It’s not just the quality; it’s that the N1 has become the statement piece of the heritage scene.

But here in Denmark, the N1 season runs from October through to early March—if you’re lucky. Any warmer than that, and it becomes an oven. I’ve found myself waiting months for the right weather to pull it out again.

For anyone living in a milder climate—California, southern Europe, Japan even—it’s practically a winter-only piece. Or something you can’t wear at all.

The Solution Is So Simple: A Lightweight N1

Iron Heart’s lightweight N1 felt like a bit of a revelation when it arrived last year. It looks the same, but sheds the bulk and heat that make the original a deep-winter jacket.

For FW26, there’s a new version: the IHM-53-ODG in Olive Drab Green.

Gone is the alpaca lining, and what you have is a water-resistant 6.2 oz. Japanese Ventile cotton, the kind of technical fabric that keeps wind and light rain at bay while letting the jacket breathe. The outer shell is still Iron Heart’s signature 12 oz. whipcord—dense and durable.

The original IHM-48 was made from a sulphur-dyed whipcord, which gradually developed fades with wear. For the IHM-53-ODG, Iron Heart has switched to reactive-dyed whipcord. That gives the olive a richer colour designed to stay more consistent over time.

The result is a deck jacket you can wear for three seasons of the year—it flexes with the climate instead of fighting it. And because it’s Iron Heart, it’s still built unlike anything else: corduroy collar, double needle seams, and a two-way YKK zipper that feels like it could hold a door shut in a storm.

The jacket is one-washed, so Iron Heart doesn’t expect any shrinkage if you ever wash it. Still, check the measurements of the IHM-53-ODG before ordering rather than assuming you’ll wear the same size as in the heavier N1.

It’s instantly recognisable, but you’ll probably wear it (even) more than the cold-weather version.

If you’re looking for the best of N1 jackets, start with this guide.