100% cotton.  A soft, white handkerchief set for the Gentleman.  Our grandfather carried these to offer to dainty ladies to wipe tears from their eyes and to wipe the sweat of Hard Work off his brow.

Classic white, goes well with a grey suit for some flash, or with a blue suit to evoke safety.  Wear with a black suit if you're daring.  As for me, I just carry them in my pocket.  Very practical.  Handy in the flu season.