I have a BOM applique quilt, Civil War Bride. I used the iron on product steam a seam, and now am trying to sew a blanket stitch around the applique, with the sewing machine using invisiable thread. It is really frustrating as it keeps breaking. I havent used it before, so I know I must be doing something wrong. Do I adjust the tension for the top thread? Also what kind of thread do I use in the bobbin? Same or can I use cotton/polyester? Any advice is very much appreciated. Thank you quilting sisters & brothers.