Machine Sewing with Heavy Threads - Tips for Success

Machine Sewing with Heavy Threads - Tips for Success

Heavy threads are absolutely stunning to work with. They can be used for quilting juicy, stand-out stitches, machine quilting bold outlines, and can create beautiful textural effects when used for thread painting or decorative machine stitching. Many people have never used heavier threads in their machines or may feel intimidated trying it for the first time, but it's actually incredibly easy to make them an essential part of your sewing arsenal!


The heaviest thread you can fit through your machine eye needle is 12wt (remember: the lower the number, the thicker the thread). Because the thread is much thicker, we always recommend the following "rules" to follow when sewing with these in your machine.

1. Always use a finer bobbin thread: It is always highly recommended to use a finer bobbin thread no matter what top thread you're using, however this rule is doubly important with heavier threads in the top. A finer bobbin thread will  greatly reduce the bulk in your stitching, resulting in better machine tension, reducing thread breaks, and improving stitch quality.

2. Use a larger size needle: A larger needle will punch a larger hole through the fabric for the thicker thread to fill, that way the thread isn't pulling as hard through each stitch. Reducing that friction will result in a better stitch quality, fewer tension problems and fewer thread breaks. A topstitch needle has a larger eye which will also help accommodate the heavier thread. For most 12wt threads, you can use a 90/14 or 100/16 topstitch needle. If you're using a specialty thread like GlaMore™, a 12wt rayon thread with a strand of metallic running through it, you can even use a 100/16 or 110/18 topstitch OR universal super non-stick needle. Universal super non-stick needles are coated with a non-stick coating that helps it glide through fibres and tacky materials like stabilizer, reducing the friction on the thread.

3. You may need to adjust your tension: Most of the time you won't need to adjust your tension when using 12wt threads, however not all machines will behave the same way. If your stitch quality is suffering or the tension feels wrong, you may need to lower or increase the top tension slightly. It may feel intuitive to only lower the top tension, but in some cases you might actually need to increase it instead. Lowering the top tension means to loosen it, increasing the top tension means to tighten it. Sew a test strip on a scrap piece of fabric. If the bobbin thread is pulling through to the top, it means the top tension is too tight. If the top thread is pulling through to the bottom, it means it's too loose.

4. We suggest increasing the stitch length: Because the thread is much thicker, increasing the stitch length will help the thread lay more like a regular stitch and not look so compressed. This will also help reduce the bulk in your stitching and help with machine tension. If a normal machine's stitch length is set to 2.0, you can increase it to 3.0.

You'll fall in love with the bold look these threads will give your projects, so give them a try and add a new dimension to your work!

Our Heavy 12wt Specialty Threads:

Accent™ - 12wt 100% rayon
GlaMore™ - 12wt rayon with 1 strand of metallic
Spagetti™ - 12wt double gassed long staple Egyptian cotton (solid colours)
Fruitti™ - 12wt double gassed long staple Egyptian cotton (variegated colours)


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