I use it for any thread that is breaking for no good reason--especially while quilting with cheaper cotton threads such as Coats & Clark. It helps control the lint build up and keep the fuzzies from rubbing and eventually snapping the thread. I run several lines of Sewer's Aid down the cone before I start and let it soak in for 30 minutes before quilting. It works very well for me. I have been doing this for at least 5 years now and my baby has only been in the shop once--for sucking a lint ball up into the tension disks! Lint is my nemesis--LOL!