One of the annoyances with using a duvet and cover is the nasty problem of the duvet and the corners parting ways. So we wake up to a skrunched up mess. And the only way to really fix it is to open the cover, reach in, straighten things out and close it up.
Here’s a better way.
Sew ties into the corner of both the cover and the duvet and fasten these ties together. Problem solved.
So, to do that, get some sturdy ribbon — I use twill tape — and cut 8 pieces 10 inches long. ( That’s total 2 meters, or 4 1/8 yards)
If you are using a tape or ribbon that frays, either run a bead of glue along the end ( any white glue will work, let the glue dry before going further) or fold the ends over 1-4 inch and sew so it stays folded. Attach one end of a piece to one corner of the duvet. Sew it in, or use a safety pin. Sew a piece on all four corners.
Repeat for the duvet cover. On the duvet cover try to put the pins, (or the stitching) in the seam allowance.
Here’s a link to another way of doing this, plus some visuals.