When a sewing project shows the bottom threads on the top side of the seam, what does this indicate about the tension?

• A. The bottom thread is too loose because the top thread is too tight
• B. The bottom thread is too tight
• C. The top thread is too loose
• D. The bobbin is incorrectly inserted

Answer: (A)

When a seam shows the bottom thread on the top side, the key idea is that stitch balance comes from how the top thread and the bobbin thread pull against each other. If the bobbin thread is visible on the surface, it means the bobbin thread is being pulled up by a top thread that’s pulling too tightly. In other words, the bottom thread is effectively too loose compared to the top thread. The fix is to loosen the top tension a bit (or adjust the bobbin tension to restore balance) so that both threads contribute evenly to the stitch and the threads meet inside the fabric instead of surfacing on top. If the bobbin were inserted incorrectly, or if the top thread were too loose, you’d see different stitch symptoms, not this bottom-on-top appearance.