Originally Posted by Borntohandquilt

You're right, this is the "Knife Edge", a very traditional way of closing the quilt from UK, especially Wales.

When all the quilting is done all three layers are cut down to one length (I cut to 1 inch width measured from the last row of quilting stitches). In the next step the batting is cut with scissors for 1 more cm or almost 1/2 inch. The backing fabric is now folded around the batting to the inside, the top fabric is also folded to the inside to the same length. Then a line of simple running sitches are sewn very near the folded line and closes the quilt.

I think it fits perfectly for that kind of quilts!