I would use a zipper instead of buttons & buttonholes.

Update and question. I think I've de died what I'm going to do and now I have another question. I remeasured the top and it is actually 100X100 so King size. I'm going to sew the bottom edge RST with the sheet and then flip so the bottom is finished. Then I'll stitch the top down to the sheet. I can't find a fleece blanket big enough (King are mostly 108 X 90) so I'm going to buy fleece and have a seam. Does anyone have experience with any online sites for buying anti-pill fleece at a decent price. I'm tempted by Wal Mart online for $4.97 per yard but will have to stop in the store to see how it feels. I'd hate to order 6 yards and not be happy with the quality. Thanks for all the suggestions.

That link doesn't open the pdf file, but this one does. The page must have been moved within the website.

http://www.amybutlerdesign.com/pdfs/...elds_Duvet.pdf

Don't forget to add ties or velcro on the inside corners of the cover so you can fasten the comforter corners to them (prevents shifting). I would also french seam your fleece edges (or serge if you can) so the inside doesn't fill up with "fleece poop" all winter long. Are you going to quilt the top to the sheet so it looks more like a quilt?

It is finished. I asked for suggestions about doing this duvet cover. I ended up attaching the top to a king sized sheet, serged the edges and did some straight line quilting on the top to keep the 2 layers together. Then I sewed fleece to the back to make a "pillowcase". My friend told me that in Norway the opening where you insert the comforter is just tied shut. Sounded good to me, so I attached ribbons every 10 inches. Never again will I do something this big. I had to take it to the church and lay out on the floor of our fellowship hall to pin it together. I didn't have room in my living room to lay it out, but did my best for the pictures. The pattern and fabric is called Harvest Spice. It was a block of the month at LQS several years ago. The pattern and fabric were designed by Nancy Murty. It is out of print now. Thanks for all your suggestions.

Looks lovely, thanks for all the updates and the picture.

Wow, all that work. It looks great and will surely keep them very warm.