Here is what an industrial sewing machine mechanic told me about lint on thread. If your machine has outside threading then the lint won't be a big problem. If your machine has enclosed threading then the lint can build up and be a problem. The amount of thread guides on the machine makes a difference in the amount of lint it collects. The more guides the better, like the older machines. If your machine has enclosed threading then use the no lint thread. Bobbin areas should be cleaned with each bobbin change and completely cleaned every few weeks.