I ordered 3 shirts in different colors for my boyfriend. Oddly, though the shirts were the same line and had tags that read identical product numbers, they were of different material. The black came in 100% polyester and had different style tags than the navy and OD colors, which were 5% elastane and 95% polyester. After noticing these differences, Boyfriend looked over the shirts again, and the 100% poly black, which was by far softer than the other two, turned out to have a heatgear logo on the below-collar-decal. It looks like we were accidentally shipped the wrong  of shirt (or maybe an older design?), but he actually likes the accidental heatgear shirt more because of the texture. He hasn't gotten the chance to compare their performances, though, so I'll come back to this after he compares the wicking, comfort, etc. while on the job.

Also, it is a loose fit and it is true to size. If you want a more fitted, not baggy, feel, order a size down.