Embroidery Thread Weights & What Do They Mean?

top 4 pro tips reasons to know your thread weight thread on embroidery machine

Thread Weights And What Do They Mean?

Thread weight describes the thickness of embroidery thread and bobbin thread. The larger the number, the thinner the thread. The smaller the number, the thicker the thread.


top 4 reasons to know your thread weight

1. Designs: Designs generally require a specific thread weight due to how the design is digitized. If the thread is too thick for the stitch area, there will be overlapping threads which could cause a bird’s nest under the throat plate. If the thread is too thin for the stitch area, the coverage will not be adequate.

letter g demonstrated with filaine 12 and poly 40

2. Needle Size: Thread weight determines the size of the needle used in your machine. (The thicker the thread, the larger the needle hole needs to be.)

a. Needle selector chart >
b. Anatomy of needle chart >

3. Coverage VS Detail: Heavy weight threads cover a larger area with fewer stitches. Lighter weight threads are used for detail work within designs and/or for small lettering.

word gunold demonstrated with Poly 40 and Poly 60 weight thread

4. Fiber Type: Take into consideration the type of fiber of your thread (Polyester, Rayon, Acrylic, Cotton, etc). Heavier weight threads tend to have more strength while thinner weight threads have less.


pro tip
gunold thread weights and their uses






  • Poly 40: The Go To Thread, Durable, Colorfast to Chlorine, Long Lasting
  • Poly 60: Small Lettering, Detail In Designs, Durable, Colorfast To Chlorine, Long Lasting
  • Sulky 40: Brilliant Luster, High Tensile Strength, Natural Fibers
  • Cotty 30: Matte Finish, Natural Fibers, Strong
  • Filaine 12: Vintage Look, Wool Like Features, Great Coverage
  • Mety 30 And 40: Glamorous Sparkle, Multiple Colors, Two Thicknesses
  • Mono 80: Transparent, Accent Designs

pro tip
helpful thread weight videos
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thread weight videos

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