Ali, I think you hit the nail on the head! My friend is new to long arm and her machine, and she volunteered to do my quilt for free, as It would be her first one to baste. She probably used the cheapest thread she could, after all, it is just basting that will be taken out later. But, what you said makes sense! I'm not sure what thread I used in a couple of smaller areas that needed VERY close basting, to easy in some excess fabric, but I thought it was Superior's Masterpiece and it caused bearding, too. Anyway, I will share this information with my friend, so she can grow as a longarmer! Thanks again, Dawn