Use what you like and what you can afford. That's the only rule I go buy when it comes to quilting products. If it's on sale I have it. I read many experts saying do not use nylon thread, it's too stretchy, too thin, too this or that. I found a big cone at 75% off. Guess what? I'm still using it after several years and it makes great bobbin thread. It doesn't melt when pressing, I steamed and used a linen setting on my iron on a wad of the thread and nothing happened. Don't use glazed or waxed thread in your machine, the residue will mess up the tension discs.