Yeah, you could buy a sweatshirt made out of cotton. Same as, if you looked hard enough, I’m sure you could find a Flinstones-style foot-powered car, and buy that, too. Or, you could buy one of these Crews from NWKC, which are made in the USA out of Merino Dual Cloth, a proprietary fabric that has German merino wool on the outside, cotton/poly on the inside, and spandex in between the two. So they’ll stretch without losing their shape, won’t get stinky, and can be washed over and over. But yeah, I guess cotton is fine, too.
For price and purchase info, visit NWKC.