The material is really great, not that shiny polyester stuff, they're more linen looking!  Blocks out lots of light but mostly for night time, (maybe because I bought the  white colored ones, it didn't seem to blockout lots of daytime light)  My only disappointments were that they were quite pricey and the grommets are a bronze color while my curtain rods were a brushed nickel so the finishes do not match, but I'm overlooking that because they look great in the room and match the bedding.