Rather surprisingly (to this editor, at least), moisture-wicking treatments can eventually launder their way right out of apparel. Though "chemically treated" clothing sounds slightly dubious, it's actually the way companies ensure consistent performance qualities from garment to garment. Natural fibers, on the other hand, can deviate slightly.
Chad Trollinger, director of marketing for Augusta Sportswear in Augusta, Ga., suggested this nugget: Distributors should particularly look for companies that do extensive wash testing on their garments. This way, they can be sure fabric extras will last a lifetime.