Down Blanket A down blanket is very similar to a down duvet. Down blankets are usually thinner and have a sewn-through box construction. Our down blanket features an attractive coordinating satin trim and is filled with high quality super washed 575+ fill power white goose down. Down blankets are meant to be a layer under your bedspread or coverlet, unlike a down duvet which goes inside a duvet cover and is often the top layer of the bed itself. Down blankets are great because they are much lighter than wool but provide similar warmth.