Thread weights
Thread Weights Explained: 12 wt to 100 wt Uses and Needles
Thread weight is an inverse measure: the higher the number, the finer the thread. 50 wt is the everyday choice for piecing, 40 wt is the standard for machine embroidery and bold quilting, 12 and 28 wt are heavy decorative threads, and 60 to 100 wt are fine threads for bobbins and invisible quilting.
Thread weight (wt) is an inverse measure: the higher the number, the finer the thread. In the common weight system, the number is the kilometers of thread that weigh 1 kilogram. 40 wt means 40 km weighs 1 kg (Superior Threads).
| Weight | Thickness | Uses | Needle | Examples |
|---|---|---|---|---|
| 12 wt | Very heavy | Big-stitch hand quilting, Bold machine quilting, Decorative topstitching, Hand embroidery accents | 90/14 or 100/16 Topstitch (Aurifil 12 wt) | Aurifil 12 wt cotton, WonderFil Spagetti 12 wt, Sulky 12 wt Cotton |
| 28 wt | Heavy | Machine quilting with visible texture, Hand quilting, Blanket stitch applique, Hand applique and embroidery | 90/14 Topstitch, Quilting, or Denim (Aurifil 28 wt) | Aurifil 28 wt cotton |
| 30 wt | Medium heavy | Decorative stitching, Quilting that should show, Some embroidery | 90/14 is a common starting point | Sulky 30 wt Cotton |
| 40 wt | Medium | Machine quilting with stitch definition, Machine embroidery (standard weight), Topstitching, Piecing | 80/12 Microtex, Sharp, Universal, or Denim (Aurifil 40 wt); 90/14 Topstitch (Superior King Tut and Fantastico) | Aurifil 40 wt, Superior King Tut 40 wt, Superior Fantastico 40 wt, Isacord 40 (polyester embroidery) |
| 50 wt | Fine | Piecing with flat seams, Garment sewing, Machine applique, Subtle quilting, Bobbin thread | 80/12 Microtex, Sharp, Universal, or Denim (Aurifil 50 wt); 90/14 Topstitch (Superior So Fine! 50) | Aurifil Mako 50 wt, Superior So Fine! 50, WonderFil Konfetti 50 wt |
| 60 wt | Fine | Bobbin thread for embroidery and quilting, Fine piecing, Heirloom sewing, Applique | 90/14 Topstitch (Superior Bottom Line); 70/10 to 80/12 also used | Superior Bottom Line 60 wt |
| 80 wt | Very fine | Invisible machine and hand applique, Heirloom sewing, Fine detail quilting, English paper piecing | 70/10 or 80/12 Microtex, Sharp, or Embroidery (Aurifil 80 wt) | Aurifil 80 wt |
| 100 wt | Ultra fine | Micro-stippling and dense background quilting, Invisible applique, Heirloom machine quilting | 70/10 Topstitch (Superior MicroQuilter); 70/10 or 80/12 Microtex on domestic machines | Superior MicroQuilter 100 wt, WonderFil InvisaFil 100 wt |
Researched from manufacturer specifications, owner manuals and verified owner reviews, not hands-on testing, and not professional advice. As an Amazon Associate, Cozy Stitchery earns from qualifying purchases.