What a wonderful hint to use unwaxed thread for upper tension. Thank you - I have a Singer 401, and oil and grease faithfully but this idea sure sounds perfect.
Originally Posted by Prism99
Since that is the back of the quilt, it looks as if the upper tension is not tight enough. If you have some *unwaxed* dental floss, try flossing between the tension discs in your upper tension. A bit of lint caught in there can cause this type of problem.
First, though, just try tightening the upper tension by 2 numbers or so and see what happens. It may be that oiling changed the tensioning requirements.