for quilting on my LA I use either a 40 or 50 wt on the top and 50 wt So Fine on the bobbin. On my embroidery machine I use bobbin thread. So this leads me to a question for the Long Arm users out there. Recently someone gave me over 50 spools of 12 wt cotton thread. It seems very thick to me. Has anyone tried to use thread that thick on your Long Arm machine? And if you did what wt bottom thread would you use. If it can't be used on a Long Arm what would I do with that many spools of 12 wt thread? My guess is that it is way too heavy for Long Arm machines. I hate waste and would love to use this if possible.