A duvet cover is just a big pillow case and easy to make. The thing is getting material that is wide enough to make it. I suggest you look at sheets. If you can find a pattern you like it would be easy to make a duvet cover and even drapes out of flat sheets. The thing about sheets is they are already hemmed. You need 2 flat sheets to make a duvet cover. Measure your duvet buy the sheets that most closely matches the cover. Leave the top hem alone and cut any excess off the bottom and sides. Make sure you leave enough on the top to overlap the seams. Now sew all three sides leaving the top open. Then sew velcro on to the hems to close the envelope

Just a thought from my own experiences. Some people use an upper sheet between their body and the duvet when sleeping. Others don't, and are in direct contact with the duvet cover itself when sleeping. This brings the breathing ability of the sheet in play, making it important. If you use sheets for the duvet cover without adding an additional top sheet between your body and the duvet over, the top sheet of the duvet cover is ok if a polyester/cotton blend is used. A polyester addition limits the breathing capability of a sheet. However, the bottom sheet of the devet cover is better if its made with a 100% cotton sheet, thus ensuring you'll not 'sweat' excessively. This is particularly important if one lives in a hot climate. Hope this helps.

Your front is definitely going to require more than the plain back ; you could use a king flat sheet for the back and save money. What is your horizontal and vertical fabric repeat ? I find store bought kings are always skimpy, here's your chance to get a generous drop; measure your bed and let us know the dimensions.

Thank you for your thoughts and comments, annie1971.. I suppose I'm trying to work something out where I might accomplish the most I can. I love my down duvet, but keep it aside with a light cotton cover on it that I made, and it seems to work fine for our needs. I also have a comforter I can cover (believe duvet covers are used to cover them as well.) I am here trying to find a way to add the colors/design of the fabric I found, to my bed, and show it, the furniture, room, etc, off - let it sort of function as a whole on another level(an enjoyable and relaxing room to be in). The colors in this fabric will bring the whole thing together... especially if I can find a way to being it together with 'function' - also important, as you indicate. I'm also trying to be practical, as regards how much upkeep any addition would need to keep it clean and look its best, with our lifestyle. Not so simple, so I appreciate all participants' input.