Proof 72-Hour Merino T-Shirt Review: Multiple 3-Day Wear Tests

In today’s review, we’re taking a look at the 72-Hour Merino t-shirts from the travel and technical fabric-focused brand Proof. They’ve got a fair few products that aim to blend classic looks with modern tech — Stridewise’s editor Nick is a fan of their stretch canvas pants — but they’re definitely best known for their “72 Hour” line.

These products are made with a blend of antimicrobial wool and durable nylon and dare to make the claim that you can wear them for 72 hours without needing to wash them, making them ideal for the traveling man — or the New Yorker who wants to put off walking to his laundromat for as long as possible. (Hi, Nick.)

I put the 72-hour shirt through multiple four-day tests (just because I enjoy overkill) and I documented these tests in multiple videos on my YouTube channel, which I’ve embedded throughout this article. Let’s find out how they fit, how they last, and if they’re worth it.

Disclaimer: Huckberry sent me these t-shirts for free. All of the opinions in this review are mine alone. I did not share this content with Huckberry prior to publication.

Pros & Cons

In a hurry? Here’s a breakdown of my experience with Proof’s 72-hour shirts.

Pros

• Super-soft and comfortable
• Naturally wicks moisture, regulates your temperature, and resists odor
• Two fits and a dozen colors for a ton of consumer choice
• Machine washable, but also easy to hand wash
• Air dries faster than cotton

Cons

• Should be washed on “Gentle” in cold water
• While they’re approved for use in a drying machine (on “Low”), I personally wouldn’t risk the damage
• They don’t smell with wear, but they do get wrinkly after day 1
• If you have even a slight wool sensitivity, you’ll find them itchy
• Some find the sleeves a bit short

How I Tested Proof’s 72-Hour Shirt

I have four 72-hour shirts in different stages of wear, from brand new to three to four days of wear without washing. I’ve been wearing these shirts for over a month.

Proof makes them out of a blend of extra soft merino wool and claims that you can wear them for three days straight without showing wear or needing a wash. I can tell you right now that it’s true — you really cannot tell that my black shirt has been worn for three days without washing, and it still smells new.

it’s true — you really cannot tell that my black shirt has been worn for three days

I’ve also done several four-day tests on the shirt, wearing the long-sleeved version on a recent work trip for three or four days straight. I mean, I changed out of them when I went to sleep, but the shirts did not stink.

In another test, I went further and wore the proof 72-hour shirt for three days straight, working all day and sleeping in it. Still: no stink. But I washed my sheets, to be safe — they weren’t as antimicrobial as a wool performance shirt.

Proof’ 72-Hour T-Shirt: Sizing & Fit

• Two fits: “Classic” and “Slim”
• There used to be a “Performance” fit, it got renamed to “Slim”
• I sized up in the Performance Fit to get a slightly tapered shirt in similar dimensions to the Classic Fit in your usual size

The Proof 72 Hour Merino Wool t-shirt has two cuts: a “Slim” fit and a “Classic” fit. Both cost $78 USD. The Performance Fit is slimmer in the arms and chest, whereas the Classic Fit is looser-feeling all around. If you like a more tapered fit that isn’t too slim, consider sizing up in the Slim fit like I did.

A few things stand out when I stack the two shirts and compare the measurements of the medium Classic and the large Slim.

The large Slim is about a quarter inch wider in the body, and about a half inch longer, but the distance pit-to-pit across the chest is almost identical. 

But the sleeves of the large “Slim” shirt, while the same length, are just a bit slimmer than even the medium “Classic”.

I appreciate both fits. I like the look and feel of the Slim fit, but once I put on the Classic shirt, I immediately enjoyed the more relaxed feel — and the extra airflow.

If I were forced to choose between them, I would stick with the sized up Slim shirt, since it’s more flattering and looks tailored-looking without being restrictive, plus I can wear it as an undershirt.

Obviously, the fit that’s best for you depends on your body, style, and preferences.

Proof 72-Hour Shirt: How They Change With Wear

I have four shirts at different stages of wear. The Oxblood shirt is brand new. The green one has been worn a couple of times but has been washed and not worn since. The black one has been washed but worn three days in a row without being washed. The teal blue has also been washed, but this is my second day in a row wearing it.

The only thing that looks different about all of these shirts is the level of wrinkles. The shirt tends to get wrinkly the more days in a row you wear it. It didn’t show signs of pilling, abrasion, or smell, and they’ve all gotten consistent wear for over a month. If anything changes in the durability department, I’ll edit this review to tell you.

Proof’s 72-Hour Shirt: Washing and Care

Unlike many other wool products, these shirts are machine-washable. My shirts have not been machine-washed yet, since I personally like to hand wash them in a basin with a little bit of Dr. Bronner’s soap and hang dry. Wool is longlasting, especially when blended with nylon like these shirts are, but I’d rather be safe than sorry.

The brand recommends cold water washes on a gentle cycle and if you’re putting them in a dryer, to run it on the lowest temperature. To me, that sounds like playing with fire: just air dry the shirt. The good news is that this weight of wool (especially when, again, mixed with nylon) dries very quickly, which is another traveler-friendly benefit.

Merino Wool 

• Stays orderless for three days
• Wicks moisture well
• Warm during cooler days

The Proof 72-hour Merino wool shirts are a revelation in terms of durability and their ability to remain odor-free. The shirt remained odorless over the first two days of wearing it as an undershirt in 80° Fahrenheit weather, even after outdoor activities like walking my dog. It wicked moisture away remarkably on those warm days.

It still exhibited excellent performance and temperature control on a cooler day during the local tomato festival. That’s another benefit of wool: it insulates well, keeping you warmer on cool days and cooler on warm days. This element is slightly reduced with the addition of nylon, to be fair.

I wore the shirt last week during a heat wave, with temperatures reaching over 90° F. After wearing it for three days straight without washing it, the shirt still showed no signs of odor. I could easily use it again if it weren’t for the wrinkles stemming from consistent wear.

Are Proof’s Wool Shirts Itchy?

A great thing about this review is you’re getting the perspective of two people who wore it: myself and the editor of this website, Nick.

He has a very slight wool sensitivity and wanted to note that although this ratio of merino wool to nylon (87 : 13) is designed to be non-itch, he still found it too itchy to wear.

Interestingly, he didn’t find that to be the case with Proof’s 72-hour pants, because they’re just 47 percent wool.

There are many levels of wool sensitivities so it’s hard to say if you’ll have the same experience, but if you have even a slight wool sensitivity that doesn’t reach the level of allergy, the shirts might not be for you.

Are Proof’s 72-Hour Shirts Worth It?

• Merino wool is more expensive than cotton, but it’s durable and great for travel
• No pilling or visible wear, even after wearing backpacks
• Price: $78

Years ago, I was hesitant about trying Merino wool products due to the high price tag involved. After wearing Smartwool socks, I found that they lasted an impressively long time and performed well in cold weather.

It’s true that I’ve only worn them for a month, but I’ve worn them very hard and noticed no degradation. Above all, they lived up to their claim that they don’t stink after multiple days of wear.

These shirts confirm why merino wool is favored by many for minimalist and nomadic travel. They endured multiple back-to-back days of 90° F heat without retaining odor and then cleaned up easily with a quick wash and hang dry. Since they can hang dry overnight, they are practical and perfect for travel.

Since you’re getting (at least) three times more wear out of this shirt before washing than with a regular t-shirt, I think the higher price is justifiable. I’ll definitely take them on an upcoming trip to Disney World and wear them for consecutive days in the hot, humid environment.

Conclusion

If you’re looking into Huckberry’s Proof 72-Hour Merino wool collection, I say go for it. I love this clothing line and am now a firm believer in Merino wool products for all kinds of wear. If you don’t have a wool sensitivity, I think they’re worth a shot.

Thanks for reading my review. Please check out my YouTube channel to catch up on my other reviews and to follow along with my upcoming videos.