Superior Thread is 'King Tut' sew fine' and bottomline' and they have a bobbin winder set up right there at the plant in Utah, USA. they also have awsome silk thread and many specialty threads.....the web site is a favorite 'dreaming' spot for me. several of my friends have Long Arm machines and they are all different brands but they all use Superior Thread and some of them have even been to the classes in Utah. check out the website:
www.superiorthreads.com