Do not despair. I am not sure about the residue, but the sewing with just the top and batting is sometimes done to hide the stitching in multiple colors. If you use newsprint paper like they use in kindergarten, becasue of the large size, this will work well. You then just tear it away. Even some cheaper wrapping paper will do the trick and comes on large rolls at the Dollar Stores. Hope this works for you.
Ellis' Granny B