I had purchased some Sulky invisible a few years ago, and I thought it kept breaking. Tried larger needle, smaller needle, tension, etc. Could not figure it out. Took it off the machine and pulled some off the spool by hand. It came off in about 12" sections. Pulled another piece, 12" or so. Looked at spool to see if it had a cut thru the thread, could not find one. It seemed as though the thread was wound with short pieces. Went and bought another spool, and tried it when I took it out of bag and it did the same thing. Took both of them back and never bought Sulky again.