Choosing the Perfect Thread Weight for Your Machine Quilting Projects
As a long-time machine quilter, one of the most common questions I get asked is “What’s the best thread weight to use?” There’s no single right answer, as the ideal weight depends on your specific project and quilting style. But in this article, I’ll break down the main thread weight options and share tips based on my experience to help you pick the perfect one for your needs.
Lightweight Thread (50 weight or finer)
Thread this thin is great when you want your quilting stitches to be barely visible. Lightweight thread is ideal for quilting on thin or delicate fabrics like batiks or silks. It allows the focus to remain on the piecing rather than the quilting itself. 50 weight thread is also a good choice when doing intricate quilting designs with lots of tight curves and corners, as it doesn’t get stuck as easily as thicker threads.
On the downside, lighter threads can be harder to see on darker fabrics, making them less beginner-friendly. They also tend not to hold their shape as well over time compared to thicker threads. You may notice the quilting stitches puckering or distorting more quickly. So for quilts that will see a lot of use and washing, a slightly heavier thread could hold up better long-term.
Medium Weight Thread (60-80 weight)
Threads in the 60-80 weight range offer the goldilocks option – not too thick, not too thin. They provide sufficient visibility without overwhelming the quilting design or hogging all the attention. 60-80 weight threads are kind of the “new basic” that many quilt teachers and longarm quilters swear by. You get good definition without the worry of stitches distorting or fabric sides rubbing together over repeated washings.
Within this medium range, 70 or 80 weight thread is what I typically reach for in my own projects. Thicker than 60 weight but not so bulky that it struggles on tiny applique pieces or fussy longarm quilting. A great versatile everyday choice that works for everything from baby quilts to large king-sized bedspreads.

Heavyweight Thread (100 weight or thicker)
On the other extreme, very thick 100+ weight threads are awesome when you want the quilting to really stand out. They make dense, puffy stippling or echo quilting really pop. Heavyweight thread is ideal for highlighting quilting on longarm machines capable of intricate design work. The thicker stitches draw attention to fancy quilting patterns and make the overall impact quite dramatic.
However, working with threads this bulky does require some adjustments to your sewing technique. Take it slowly through tight curves and you may need to retrace areas to prevent stitch distortion. 100+ weight thread also doesn’t work as well for tiny pieces or needle turn applique. So it’s best reserved for projects where the quilting, not the piecing, is the main focus you want to feature.
Choosing Thread Weight Based on Fiber Content
The fiber content of your thread also deserves consideration when choosing a weight. Generally speaking, polyester and cotton blends provide a nice middle ground that works for most purposes. But 100% polyester threads tend to be more smooth and silky feeling, so you could size down a thread weight if using one with a high poly content.
On the flip side, 100% cotton or mercerized cotton threads have a bit more substance and structure to them. So if using an all-cotton thread, you may want to go up a weight compared to what you’d normally choose with a blended or poly thread.
Other Factors to Consider
Beyond thread weight alone, take into account details like the quilt fabric, intended use, and quilting motif when deciding what’s best for your specific project. For example:

- Heavier quilts = heavier thread to prevent stitches from sinking in over time
- Delicate quilting motifs = finer thread so details aren’t obscured
- Dark fabrics = slightly heavier thread for better visibility
- Quilts for kids/pets = heavier duty thread to withstand tough love and washings
You may also want to do some test swatches with different thread weights on your quilting fabric scraps before diving into the big project. See which weight leaves stitches you like the look and feel of best.
Experiment and Find What Works for You
Ultimately, there’s no single right or wrong answer when it comes to thread weight. The best way to determine what you prefer is to try different options and see what vibe you dig. If a lighter thread starts distorting after a few washes, size up. If a heavier thread is a chore on fiddly piecing, go thinner. With some experimenting, you’ll discover the goldilocks thread weight groove that makes you happy!
So don’t be afraid to play around until you find what works best for your style and specific needs. Different projects call for different solutions. But hopefully this overview has given you some helpful guidelines and food for thought next time you’re picking out thread for your machine quilting projects. Now get out there and start quilting – but maybe bring an extra spool along in case you want to test drive another weight!
Let me know if you have any other quilting questions! I’d be happy to chat threads and techniques some more. Sew long for now!
Thread Weight Recommendations for Machine Quilting
Thread Weight | Fabric Type | Needle Required | Stitches Per Inch |
---|---|---|---|
50 weight | Lightest weight fabrics like batiks and lawn | 80/12 | 15-25 SPI |
60 weight | Most quilting cottons and light to mid-weight fabrics | 90/14 | 12-18 SPI |
80 weight | Denim, canvas, mid-weight cottons | 100/16 | 8-12 SPI |
100 weight | Heavy denim, upholstery fabrics | 110/18 | 6-10 SPI |
FAQ
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What is the best thread weight for machine quilting?
Generally speaking, 50 weight cotton thread is a good all-around choice for most machine quilting projects. It’s not too heavy that it strains your machine or causes thread breaks, but it’s also not so light that the stitching looks sparse or uneven. 50 weight thread is kind of the happy medium.
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Should I use different thread weights for piecing versus quilting?
You may want to consider using a lighter weight thread, such as 40 weight, for piecing your quilts. This will help minimize the bulk that thicker thread can create when sewing through multiple fabric layers. Once the quilt top is done, switch to a 50 or 60 weight thread for the actual machine quilting process. Heavier thread stands up better to the tension of repeated stitches through the quilt sandwich.
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Is 60 weight thread too heavy for machine quilting?
While 60 weight thread does provide excellent coverage and durability, it can be a little much for domestic sewing machines to handle smoothly. 60 weight thread is pretty thick, so it puts more strain on your machine’s mechanism. This means more risk of skipped stitches or thread breaks. So unless you have a heavy-duty longarm quilting machine, 50 weight thread is often a safer bet.
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Is 30 weight thread too light for machine quilting?
Thread this light runs the danger of being almost invisible against fabric with a busy print or deep tones. The stitches may also pull out or become distorted over time with heavy washing and use. For best results, you’ll want at least a 40 weight cotton thread minimum. While lighter thread is okay for piecing, most experts recommend 50 weight or heavier for the actual machine quilting process.
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What about polyester thread for machine quilting?
Polyester thread has its place, like for quilting non-cotton fabrics or fast piecing projects. However, cotton thread is generally a better selection for machine quilting cotton quilts. It has a soft hand that doesn’t show through the fabric as much as polyester. Cotton thread also breathes better, which is important considering how much washing and use quilts tend to get. So in summary – stick with cotton if possible.
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Can I use different thread in the bobbin for machine quilting?
You definitely want to use the same weight and fiber content (cotton vs polyester) thread in your bobbin as you do on top. Mixing thread types can lead to uneven tension or inconsistent stitch formation. Nevertheless, a slightly different color thread isn’t the end of the world for the bottom. But best practice is still to match thread above and below. Consistency is key for quality machine quilting results.