I don't know whether I'll ever try the monofilament again, at least on my current machine that holds the thread in only a horizontal position. It was a brand new spool of Sulky, so a good brand. I know other people said putting it in a cup worked. I think it wasn't coming off the spool quickly enough. I had put the tension down to 2. I am taking a Craftsy FMQ with Leah Day and asked her about monofilament thread. She said she never uses it because she prefers to have designs show after all the work she put into them.