Very lightweight, almost flimsy cotton.  Two of the buttons popped off while I was undoing them just to put the shirt on the first time.  The contrast colors are very nice and the pocket hankie and tie are decent material.  Unfortunately, those are the only two usable pieces, as the shirt is simply not good enough quality to go with a nice suit or pants.  Nevertheless, if you decide to wear it, wash it on gentle cycle, as it most likely won't last long.