Are you able to take a picture of your quilt? Maybe it would be easier for someone to advice.

The comment from Lois is the correct way to do the cuts to make it rag after laundering it.

To get it to "rag" you should snip the seam allowances about every 1/4". Then wash it--preferably more than one time. I made a cotton (drawstring) bag in which to wash my rag quilts, because they can stop up your washer and dryer. Cotton will not "rag" as much as flannel, but it will happen, and a little more with each washing.

Yes, you do need to snip the seams. Be careful not to clip the stitches.

Just washing my fabrics for I spy swaps partially stopped up my sewer line. When the DH ran the snake through the line, he said it looks like "mop strings". Since I am dealing with larger pieces, I bought some lingerie bags to help with that problem. I'm not sure it would help with the finer fraying of a rag quilt. You might put a drawstring in an old pillowcase which would be much like Wanda's cotton bag.

bk

How brave are you?

http://www.flynnquilt.com/free-lessons.htm

"Use an electric “Weed Eater”, not the
more powerful gasoline model. Just angle the head of the tool so the
plastic cord whips the quilt’s edges to fray them. You can see how well
you are doing as you go. Keep after the edges until they are all fluffy."

Not that brave.

OK, I am pulling my hair out now. I have cut it every quarter inch and washed and dried it several times. It just won't rag. And it was supposed to be a Christmas present. Clerk at Joann's fabrics says cotton won't rag, only flannel. Another one says its the dye. Neither of those seem logical to me.

It finally ragged! I bought ragging scissors, which I highly recommend. Then made cuts every 1/8th of an inch apart. That was my first and last rag quilt!

Don't give up. The non-ravely fabric is to blame.
A good ravely fabric makes a lovely rag quilt.

Cotton does rag, I've made several... I love making rag quilts but I always take them to the laundry mat to wash them the first time.