Momyar

I've got one that I'm going to do the same thing to. I have my top pieced but not sewn together yet. I plan on taking a sheet and quilting it to the top and then using another sheet for my backing. Then put the down bed inside.

Good luck!

familyfun

One of my first sewing projects I did was make a duvet cover for my goosedown comforter. It is King size and by itself that sucker weighs about 2 tons. I put buttons across about 3/4 of the bottom to close. But I gotta tell you of the time I dont even put the comforter in it. It is way to hot. I use it by itself on the bed. I also made matching curtains.

MsEithne

I've made goose down duvets. One of the things that gives them warmth is leaving ample room in each compartment for the goose down to fluff up freely. What makes a goose down duvet warm is the ability of the down to trap the warmed air.

If you squish too much down into a compartment or if you make the compartments tiny (such as would happen with most quilting) you will lose the insulating qualities of the down. It won't be able to fluff up properly to keep you warm.

Another problem is washing. The whole reason to have a duvet cover is to protect the fabric and goosedown from skin oils. Each time you have to wash the down, it never quite recovers the amount of loft it had originally, so it is in your own best interests to do whatever you can to minimise the number of washings.

MsEithne

A caution for those who make quilted tops to cover the duvet. If the top is too heavy, it will squish the down and cause it to matt together (the fluff gets all tangled together) and will reduce the insulating properties of the down.