Very thin ( in a good way!) and warm.  A nice, bright true white.  Provided extra warmth without bulk under my parka for an 6 hr.  hike w/ my dogs in 18 degree  weather.  Columbia runs true to size -- no vanity sizing here!  Bought a large to accommodate layers.  This was the first vest that wasn't tight across my chest(34 G bra size). I was able to it as a warehouse deal so I am thrilled to have this under 43 dollars!