When it's a bath mat!
My daughter had a duvet cover that has seen better days. The ribbon embroidery had started to come undone, there were bleach spots (no idea how they got there) and the fabric was worn in places. Since we try to recycle and reuse as much as possible, I decided to make a bath mat from the fabric instead of throwing the cover away.
I first removed the buttons. These go into my button tin. Every grandma should have a button tin. Kids can spend hours on a rainy afternoon sorting through old buttons, putting them into shape, size and colour groups and patterns.
Next I cut the duvet cover into very long lengths of fabric. Most people will tell you to make slits at 1 inch intervals along one edge of fabric and rip the pieces so that you get even-width lengths. You then have to sew the lengths together to make "yarn". This was going to be a very simple bath mat, so I decided just to cut on a gradual spiral, roughly 1 inch wide, until I got to the top of the duvet cover. Then I cut along the top edge so that I had 1 continuous length of fabric to work with. As the side seams would naturally unravel because I had cut through the stitching, I just tied knots in the fabric to secure the seam pieces.
Next I took the biggest crochet hook I own (9 mm I think) and made a magic loop. I made 8 single chain stitches, and then worked in the round, increasing regularly by working 2 stitches into one hole until I ran out of yarn. The inner rounds are single chain, and the outer rounds are trebles.
The finished bath mat is approximately 24 inches in diameter.