I use lots of invisable thread . I do like the invisble from Superior thread. Contrary to what many use... I find I have the best sucess with the smallest needle 70/10. The thread is so fine there is not much need for a big needle. Letting the thread relax is important for sucess as well. Just last night I was using some on a spool and not a cone... I set the spool a good 6 inches from the machine and let it feed. Most machines work best with invisable when the upper thread tension is loosened, each machine will have its own "adjustment" factor .. so do have a sample sandwich to fine tune the tension.