The fabric is rayon & poly which means its as bulky as wool but not nearly as warm.  I don't like the fabric at all but will probably keep the shirt because I need the color.  This type of fabric is a pain in the neck b/c it dries very slow but you can't put it through the dryer.  Its not the nice thin rayon which makes a good base layer.  Its too thick to be a good base layer.
I am a USA size 6-8 and large fit.