Quilt binding lives a hard life.
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| What thread weight is best for mending a quilt binding? |
This quilt, Strike Zone, is a case in point. Strike Zone was finished in 2010 and is frequently used—on the couch, in the recliner, around the shoulders. It’s a large lap-size, raw-edge appliqué, flannel quilt with a cotton backing and binding, and a cotton batting. It has a nice drape, is soft, snuggly, and well-loved.
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| Stitches are broken and the binding has pulled away from the body of the quilt. |
As with Strike Zone, the binding edge of a quilt is the part that gets tucked under, tugged, folded, wrapped around cold feet (yes, with slippers still on), and gripped during every use. Unlike interior quilt seams, the binding endures more tension and wear. So, when I was notified that Strike Zone’s binding needed a little TLC, the thread choice was especially important for mending the areas that were breaking away from the body of the quilt.
Understanding thread weight and ply
In my recent Intro to Free-motion Quilting class, my students and I talk about thread weight and ply. Understanding what these terms mean is valuable when choosing threads for certain quilt-making tasks. For the task of mending a quilt binding, I’m focusing on 50 wt thread.
- Weight has to do with thread thickness. It’s calculated by determining the number of kilometers of [one ply of] a thread that is needed to equal 1 kilogram of weight. 50 kilometers, in this case of a 50 wt thread.
In the thread weight numberingsystem, a higher number means a finer thread. In the range from 12 wt (quite thick/heavy) to 100 wt (very, very fine), 50 wt sits somewhere in the middle of the pack and is commonly used for piecing and quilting.
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| Comparison of a 50 wt 2-ply cotton thread, a 50 wt 3-ply, and 40 wt 3-ply. |
- Ply refers to how many strands are twisted together to create the finished thread.
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| Illustration of “ply.” From Harmony Yarns. |
- 50 wt 2-ply = two fine strands twisted together
- 50 wt 3-ply = three fine strands twisted together
Even though both are labeled “50 wt,” the 3-ply version is typically rounder, stronger, slightly thicker, and more substantial.
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| A 3-ply 50 wt cotton thread from WonderFil Threads. |
Lesson learned
When deciding between 50 wt 3-ply cotton thread and 50 wt 2-ply cotton thread for quilt binding, the answer was much clearer during the mend than it was at the time the binding was initially attached. The answer for mending a binding was a resounding 50 wt 3-ply! I wish I would have chosen a 3-ply thread initially over the 2-ply that was used. (It was probably a color-match reason originally for using the 2-ply.) But I’ve now learned this lesson.
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| Strike Zone’s label also needed mending. |
Why 3-ply is a winner for quilt bindings
A 3-ply cotton thread has a rounder, denser, and stronger structure that tolerates use and wear much better. Its structure is less likely to pop or snap under tension. Over time, 3-ply generally survives use and care of the quilt’s binding longer. A weak or overly delicate thread can fail long before the repaired binding fabric wears out again.
For longer-lasting bindings, and fewer repairs, stronger thread is usually the smarter choice. Especially for:
- everyday quilts
- children’s quilts
- bed quilts
- frequently washed quilts
- donation or charity quilts
- utility quilts
The 3-ply thread will definitely outlast the 2-ply on this quilt.
When to consider a 2-ply thread?
Even though 3-ply is preferable for the quilts I make these days, there are situations where 2-ply might be advantageous for certain projects.
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| Three cotton threads (from left): 50 wt 2-ply, 50 wt 3-ply, 40 wt 3-ply. |
Vintage or Antique Quilts. Older quilts can have worn or fragile cotton fabrics that no longer tolerate firm stitching. A softer 2-ply cotton thread can be more gentle, flexible, and reduce the risk of damaging or tearing weakened vintage fabrics.
For antique quilts and delicate vintage textiles, preserving the textile is often more important than maximum strength and durability.
Invisible Hand Stitching. If you’re repairing a quilt with tiny hand stitches—such as a vintage or heirloom quilt—and want the stitches nearly invisible, 2-ply can blend more easily into the cotton fabrics. A 2-ply cotton thread creates flatter stitches and has less surface visibility. It’s a bit more subtle and can provide a softer hand—but to the detriment of thread strength.
But not for garment sewing! On a side note, I will not use a 50 wt, 2-ply cotton thread when sewing garments. Another lesson learned from a real life experience. Use a thread with a poly content—either a cotton covered poly core or an all-poly thread. (It will prevent the back seam of your pants from splitting!)
Final Thoughts
For most cotton quilt bindings and repairs, a 50 wt 3-ply cotton thread is the safer, long-term choice because quilt edges endure constant stress and abrasion.
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| Strike Zone, a flannel, ragged edge appliqué quilt. |
The best binding repairs don’t just hold the quilt together—they preserve the character, flexibility, and life of the quilt itself.
