No space-age material here!  This is innovative winter underwear of a traditional, natural material: tightly woven cotton, half again as heavy as the thickest Beefy Tee.  As I avoid dyes next to my skin I chose the "Natural" color, a pleasant off-white that looks...well, natural.  The maker's logo in tasteful size appears on the left chest--a mark of pride.

This would work best as a middle layer, in my view, under a shirt and over a moisture-wicking inner layer of polypro or silk.

If you are broad shouldered or have a thick neck you may find this crew neck undershirt binds, but wait a bit.  After a few wearings the material actually will adjust itself to your body contours, stretching slightly where needed.  The sleeve length is accurate with some extra material to create a longer body length than a standard tee shirt, as another reviewer noted.

The high quality of the fabric ensures there is little shrinkage even after repeated washings.