I think that it is recommended to assemble the lace, then stitch around the material portion of the designs. I have only done one or two projects with FSL lace edging. It is recommended that you do not wash away the WSS until after the edgings are assembled. When done stitching all parts together use 505 spray and place the lace edging on top of a layer of fabric. Carefully stitch using a zigzag stitch on your sewing machine to the fabric on the edge of the lace. Now cut away the outside of the fabric under the lace, be careful not to cut the lace or damage the zigzag stitches that secure the fabric to the lace. Now you can rinse your project in warm water, (if you want a softer project rinse again in fabric softner project. I wish you luck - and please let us see your project