I LOVE invisible thread. I have only used Sulky so far and have not had a minute of trouble with it. When I applique with it, I set it on the upright spool holder, use size 60 Sharp needle, adjust my upper tension to 2.5 on my machine and use it in the bobbin (half full) and applique away. It works great for the invisible machine applique method, especially that I don't have different threads to match all my pieces, so invisible to the rescue! I have occasionally used it for quilting (especially great for STID) and use a size 75 quilting or top stitch needle for that. A teacher at a LQS told me once and she personally recommends YLI for people who have troubles with other brands on their machines, she said she's seen a lot of success with that brand on different machines. I wouldn't know, never used it before.
Do show us those blocks
