Quote:
Originally Posted by
dah328 
It says that it's made of polypropylene.

He may have gotten a garment in the same design, but a different fiber than the ones he owns.
But fiber doesn't mean a whole lot in terms of performance gear. the properties of this stuff depends a lot on the often complex weave- for example, a wicking shirt will often have a weave that uses thicker and looser thread on the outside than the inside, with the finer stuff drawing water off the skin, and then the thicker stuff on the outside, with more absorption capacity, draws the water away from the inside to the outside, where it can stay away from the skin and then evaporate. Keeps the stuff driest on the inside and helps the moisture evaporate faster. There are other methods, and there are also shirts that don't do that at all, and are just plain mesh. I have cheaper mesh shirts and I have a nicer one or two- the cheap ones feel like a synthetic sticking to your skin. The nice one? I've worn it for 2 weeks straight canoing and never had it feel uncomfortable. Both are made out of exactly the same stuff, run of the mill polyester. But the weave of the fabric and texture of the fiber (which can be altered with synthetics, unlike natural fibers) can make a very large difference.
That polypro shirt looks like a wicking waffle knit- meaning it'll pull the moisture away from the skin and has the little waffle pockets to lock in warm air. And polypro, as a fiber, tends to keep you pretty warm.