Up until I embraced one-bag travel, I was a natural fiber guy. And I guess I still am. I love wearing a lightweight Egyptian cotton aloha shirt, or a fine wool power suit. And cotton undies, well, they’re just the ticket. When one only has to worry about comfort, and has the means to ensure crisp appearance of natural fabrics, and the luggage to carry it, well then, they’re great. But one-bag travel imposes some constraints and compromises for which many natural fabric clothes are not ideal. Those include:

1. Compactability: you can ball or compress just about any fabric, but tech fabric survives that process better. If you employ the bundle packing method, you can reduce your unwanted creases and wrinkles, but the positive effects of bundling is amplified further with tech fabric. You might say: “Who cares about folding/creasing/wrinkling performance gear?” I would agree, but these days, quality tech fabric is found in suits, dresses, blazers, dress pants, etc., and that availability increases your odds of successful, one-bag travel.
2. Size: natural fabric clothing is generally bulkier than tech clothing, especially in the shoulders of constructed dress wear like suits and blazers. And if your goal is carry-on one-bag business travel—for most, the “carry-on” part is impl;icit, but I wanted to make sure—then a traditional suit is going to complicate the rest of the packing. It’s best if it’s worn en route, with perhaps a secondary blazer and pants in the bag. If you’re headed to a hotel with good, fast laundry service, and depending on your time frame, send both outfits to laundry as soon as you get in your room. You will never regret it. [If you’re ultra-cautious, send one at a time.] It was good enough for Cary Grant, and it works for me.
3. Weight: natural fabrics are generally heavier than tech fabrics. Weight matters in this venture, and it’s the thing for which you most often trade some convenience
4. Humidity & Perspiration Control: as good as natural fabrics feel, they do not wick moisture. They absorb and retain it. Tech fabrics wick moisture away to help you cool off better, but some are notorious for odor retention. There is debate about whether Merino wool actually wicks moisture away or simply is even better than other wools at keeping you comfortable while wet. This is an important consideration for socks, especially when hiking in cold weather.
5. Cleaning: One of the biggest problems with natural fabrics is that cleaning them and restoring them to acceptable appearance is so much more difficult and time consuming. In my experience, I can more thoroughly wash tech fabrics more quickly, and except for Merino, there is no question tech fabrics dry significantly faster.

Disadvantages of tech fabric include:

1. As noted above, odor retention. I don’t know whether it’s the polyester or what, but I come back stinkier from an extended walk, especially in the pits, with tech fabrics than natural.
2. Fit and feel. It was once true that artificial fibers never felt as good, or looked as good, as natural ones. That was certainly a big reason why, as a young professional, I adopted natural fiber clothing. But I am here to tell you that has all changed. Modern tech fabrics look almost as good as the most expensive of natural fiber clothing, and they feel just about as good as well. Sometimes better. If the clothes you buy require a tailor to get them right for you, there are tailors who might not like working with some of the modern tech fabrics. That’s usually a problem you only have to solve once.

So, what does this mean for one’s choice of fabric? It usually militates in favor of tech fabrics. But there is a wrinkle or two (sorry) on this I think you should consider. time, frequency, and temperature. With the respect to the last, if you are engaged in any form of exertion in cold temps, Merino has some real advantages. This is especially true with whatever layer you have next to your skin, and especially on your feet. I know Doug Dyment at OneBag.com ardently favors synthetic fabrics, especially in socks. And as a general rule, especially if you are doing laundry in your room, I think it’s good advice. No natural fiber is as easy or quick to wash and dry. But for the cold, a base Merino layer is superb. [Cold temps naturally complicate one-bag travel, but it can be done.] If you travel to a cold climate, say Iceland, you can wear it on the plane to prevent overloading your bag. And you can wear that base layer for days, without requiring laundering.

Which brings me to the topic of frequency. If you think you will be wearing certain items frequently, with little time for laundering—let’s be honest, it’s not about the washing; it’s about the drying—and you don’t have the luxury of taking lots of items, as in one for every day, then I think the advantage swings to Merino.

Similarly with time. If you’re taking your one-bag trip for a week or less, you can probably pack a workout or t-shirt for each day of the week, without requiring laundry. So, stink or not, you don’t have to worry about drying time or walking around smelling like a barnyard. [But do bring a laundry bag with a vapor barrier or some such along.] If you have that luxury of a short trip, then pick what you like.

I’m still a bit on the fence on this topic. And oddly enough, as a die-hard natural fiber guy, it’s because modern tech fabrics have truly startled me with their progress. I did all-tech on my last trip putting the Red Oxx Mini Boss through its paces. On my next one-bag trip, where I will be trying out the Red Oxx Sky Train, I plan to do an all-Merino inventory. On the previous trip the “synthies” did well, but the Saucony socks (I think I’ll stick with DryMax pending a Merino test) and Vuori Kore shorts did not dry as quickly as I hoped. I loved using them, but drying took longer than expected.

At the end of the day, I guess “it depends,” I think it makes sense that for certain items—suits and dress shirts, for example or certain athletic endeavors—modern synthetics are amazing. But for others, such as undies and layers, the usage circumstances need to be considered first. Merino might cover some of those bases better. But in my view, it’s the only natural fabric in the running for one-bag travel.

Update 20210919: After a couple of trips, and daily tests and comparisons here at home, it really is no contest. Merino wool, with only a few exceptions, makes a better travel fabric. And a better at-home fabric. There is nothing I have found in Merino that bests the Bluffworks suits and”dress shirts.” If you need those, check them out. But for day in and out casual and exercise wear, I am sticking with Merino. Just for fun, I wore a Merino t-shirt from Ibex four days in a row for my daily walk, that alternates 5.x and 10.x miles. I get sweaty. But overnight, each night, the shirt dried out draped across the top of a clothes hamper. It didn’t smell fresh, but it didn’t smell bad. But even with the very good Vuori performance t-shirt, sweat stink was intolerable after just one use. It came out fine with a wash, but the shirt would not have been fit for human company without it. Same was true of a comparison of my Smartwool lined workout shorts and the Vuori Kore synthetic lined short. Both are extremely comfortable. The Vuori has a fit and drape I prefer slightly. But it needs to be washed after each use. The Merino does not. Same with socks. While DryMax makes some superb, quick drying, and comfortable synthetic socks, I prefer Merino, preferably by Fits or Darn Tough.  If you go looking for Merino, I have found good products from Unbound Merino, Smartwool, WoolX, Wooly, and Duckworth. But Duckworth is the only brand that sources its wool from Montana Merino sheep, and pays American workers to make the cloth and fabricate the clothing; sheep-to-shelf American made. Check ‘em out. Pay attention to fabrics. Not all clothing made with Merino is made 100% from Merino, and sometimes a blend is the right choice. Almost every one of these makers uses a blend in one or more of their products. And good luck. Regardless of what I or any other reviewer says, your comfort is up to you.