It is a piece of material that is about an eighth of a yard. A lot of people use it for quilting. Don't worry about it unless you sew most people don't know what they are.
I am going to have to change the add because the smaller piece is not as big as I thought it was.
How long does the fabric have to be? I might have a few more pieces I could throw in. I bet those dresses are really cute. Can't imagine what they look like. If you put one on listia please let me know so I can see one.