We like to think of the perfect stitch as a love affair between the top and bottom threads.
But no relationship is automatically perfect.
Most sewing machines are pre-set at the factories for sewing garments with a mid-weight thread on mid-weight fabric.That's fine if you're sewing clothes but what if you're doing something else? If you are quilting multiple layers, stitching heavy or light weight fabric, doing appliqué, free-motion embroidery or embellishing you may find that the top tension is too tight.
Look closely and you’ll see the top tension is pulling the bobbin thread to the top.
Here's a good close up showing what the stitching looks like when the top tension is too tight. Notice how the top thread is pulling the bobbin thread up through the fabric layers to the top. You can see this especially around the curves. Some people call these 'eyelashes'. Eyelashes show up on curves when the top tension is pulling the bobbin thread up to the top fabric.
In the following close up photos you can see skipped stitches as well as the thread shredding and breaking.
Notice how the top pink thread is pulling the bottom red thread to the top.
Here you can see how the tight top tension is causing skipped stitches.
Turn your tension dial to the left:
Look at the metallic top thread showing up on the back.
Simply turn the dial to the right to tighten the tension.
as a love affair between the top and bottom thread.
will keep you stitching
happily ever after.