I use 50wt Aurifil on my HQ16 quilting machine...Tried less expensive thread by it kept breaking and skipping then tried Aurifil and "Harriet" loved it and just purrs right along... I mostly piece with Aurifil beige, black thread but when I need other colors I am using my stash of Coats & Clark on my machines. I have a 301 Singer in a cabinet, 158 Kenmore also in cabinet, a 20' featherweight and a 2014 Kenmore....oh yes and a sick viking