These flannel shirts are made from recycled plastic and tree nuts, and they're some of the softest we've ever worn (2024)

When you buy through our links, Business Insider may earn an affiliate commission. Learn more

• Outdoor startup United By Blue recently launched a collection of flannels for men and women called Responsible Flannels.
• United By Blue Responsible Flannels are sustainably made from organic cotton and recycled polyester from post-consumer and post-industrial plastic, plus corozo buttons carved from Tagua Palm nuts.
• Business Insider's shopping team tested the Responsible Flannels and found them to be warm, easy to wear, and exceptionally soft.
• The $78 (currently $69.99) price tag might seem like a lot for a flannel shirt, but we think they're a solid value for the quality and sustainability factor.

Flannel shirts are a true cornerstone of a cold-weather wardrobe, and rightfully so. They're comfortable, cozy, easy to wear, and significantly warmer than traditional cotton or linen button-up shirts.

You can find this common style at just about every casual clothing retailer during the fall and winter seasons — but growing outdoor brand United By Blue recently launched a collection that stands out in many ways.

Simply named The Responsible Flannel, the shirts are sustainably (and of course, responsibly) made with organic and recycled materials. The collection includes traditional flannel shirts for men and women, as well as relaxed-fit flannels and flannel dresses for women.

The brand sent us some of the men's flannels to try, so that's what our reviews are based on below.

About the materials

With a hefty 6.7-ounce weight, the flannel material contains a blend of 59% organic cotton, 39% recycled polyester made from post-consumer and post-industrial plastic, and 2% spandex that gives it just the right amount of stretch. The fabric is complete with a double-brushed finish for a super-soft feel.

United By Blue also uses buttons made from corozo, which comes from the nut of Central American Tagua Palms. One tree can produce up to 50 pounds of nuts per year, so the material is renewable and far more sustainable than the typical plastic buttons.

United By Blue's impact on the environment

For every product sold,United By Blue removes one pound of trash from the world's oceans and waterways. At the time of writing this review, they've removed more than 2.2 million pounds of waste. While simply buying a United By Blue product is a way that customers can help support the environment, the brand also allows them to actively participate in cleanups. If you'd like to contribute by joining a community-based cleanup, you can sign up here.

Check out our reviews, below:

Whenever I get dressed, comfort is almost always my top priority. Fortunately, the dress code at the Insider Inc. office is rather casual, so my style doesn't change much between the workweek and the weekend, and I've found myself practically living in United By Blue's Responsible Flannels this winter (I currently have four colors).

As I mentioned before, you can find flannels just about anywhere, but I keep going back to Responsible Flannels because they're the most comfortable. The double-brushed finish of the flannel feels great against your skin.

In terms of style, United By Blue executes the classic flannel look well with attractive plaids, checks, and striped designs to choose from. In the picture above, I paired mine with my current favorite Outerknown S.E.A. Jeans, which are also sustainably made, and the Timberland Courma Guy Boot, which I named the best sustainable boots for fall.

I love that it's gradually getting easier for consumers to fill their closets with sustainable pieces from head to toe, and the United By Blue brand as a whole is becoming one of my favorite places to shop for environmentally-friendly clothing. — Amir Ismael, Insider Reviews reporter

My normal work outfit is a pair of jeans and whichever dress shirt I pull from my closet at random. This routine almost always changes when my weather app tells me it's going to be a gloomy, rainy, or frigid day. If that's the case, you'll catch me in a cozy sweater to ensure I stay warm and comfy during my commute and at my desk. I recently tried the Responsible Flannel from United By Blue, and it flipped my normal system on its head. It's soft like one of my go-to bad-weather sweaters, but it looks like your standard flannel dress shirt.

Beyond being super soft, the shirt is especially warm, mainly due to the thick and fuzzy fabric made from organic cotton, recycled polyester, and just a hint of spandex. Wearing the shirt feels like I'm wrapped in a snuggie that's been genetically altered to look like a work-appropriate shirt.

I have found that the wrist-collars tend to unbutton themselves easily which is a little annoying, but it hasn't deterred me from picking out my United By Blue flannel whenever I see that rainy cloud pop up on my phone. — Danny Bakst, Insider Reviews senior content producer

I'm not much of a flannel guy these days, but that's not to say I don't love, appreciate, and wear the stuff. Lately, we've all seen a lot of brands making the push toward more sustainable clothing. Recycled water bottles, polyester, and down, as well as down alternatives. In the case of flannels, I've found a lot of Brillo-y, borderline abrasive conceptions. They've looked great and been completely durable, but tend to make me feel like I'm wearing a hemp sack. I'm all for more sustainable anything and everything, regardless of the fad or the motive, but it's got to be functional and competitive.

United By Blue's Responsible Flannels are silky soft along the lines of a really high-end brushed cotton. Effectively, you're getting the feel of a flannel that runs in the $150 range for about half the price. Stylistically, these are pretty run-of-the-mill flannels, but that's a good thing. Flannel bears a timelessness that is, to me, kind of silly to mess with.

It's more lightweight than other flannels I've tried, but a tight weave keeps you relatively warm. It hasn't pilled (yet) over a few washes, and hasn't shrunk a bit. I'm 6'1", and quite possibly the skinniest, lankiest bag of bones ever to pace the earth (or wear flannel) and it fits just right. Stockier gents, especially those around six feet tall, might want to up a size, but that comes down to style, and you do you, dear reader. — Owen Burke, Insider Reviews senior reporter

The bottom line

The $78 price tag might seem like a lot in comparison to readily available cheaper flannels, but the difference in comfort is like an itchy wool sweater that's borderline unwearable compared to a high-quality cashmere sweater. Simply put, it's worth the extra money.

With comfort, style, and sustainability going for the United By Blue Responsible Flannels, we highly recommend adding them to your cold-weather wardrobes.

Shop the United By Blue Responsible Flannel Collection now.