I'm trying to set up my Janome 4800 for machine applique using YLI invisible thread. I am having trouble with the invisible thread being very tight and breaking often. I've tried loosening the top tension and adjusting the pressure dial at 2. Also, each time I sew a 3-4" sample section, I get a line of stitching that looks like the seams that used to be sewed onto pant legs to look like a permanent crease. It is raised and very obvious. I also tried Sulky polyester invisible with even worse results. Can anyone help?