The intent of this purchase was exclusively for travel. These briefs are a cotton polyester mesh. I also purchased the Hanes Men's 5-Pack Comfortblend Dyed Brief with FreshIQ, also sold at Amazon, which are rayon and polyester.
As other reviewers have noted, the sizing is on the small side. I am normally a medium, but the large size has a comparable fit to my regular cotton medium. So upsize one notch, and you should be OK.
When traveling, weight and mass are of great importance. My regular cotton briefs weigh 2.5 ounces, but these briefs weigh only 2 ounces. While that may not seem to be a big deal, these briefs take up less space. We use compression pouches, and I can barely stuff 8 cotton briefs in the pouch. I can pack 10 of these briefs in the same pouch, and it is easier to compress. Keep in mind that airlines are imposing stricter rules with luggage. Before you know it, those ounces add up into pounds.
These briefs also, (predictably), dry faster.
The large size fits me well, and is not uncomfortable in any way. Frankly, it is hard to tell the difference from my regular 100% cotton briefs. The mesh is not particularly rough, and may be preferred, as they do contain cotton.
I can thus recommend these briefs as well as the polyester/rayon type listed above. By the way, the price here at Amazon is less than at the online Hanes outlet store.