Understanding Thread Weights

A Simple Guide to Choosing the Right Thread Weight

If you've ever picked up a spool of thread and noticed numbers like 12 WT, 40 WT, 50 WT, 60 WT, or 80 WT, you may have wondered what they mean.

The good news?

You don't need to memorize thread weights to become a confident sewist or quilter.

Once you understand one simple concept, thread weights become much easier to understand.

What Does "Thread Weight" Mean?

Thread weight refers to the thickness of the thread.

Here's the part that often surprises beginners:

The smaller the number, the thicker the thread.

The larger the number, the finer the thread.

For example:

• 12 WT is much thicker than 40 WT.
• 40 WT is thicker than 50 WT.
• 50 WT is thicker than 60 WT.
• 60 WT is thicker than 80 WT.

Once you remember that, thread weights become much less confusing.

The Most Common Thread Weights

12 Weight

A thick decorative thread often used for:

• Hand stitching
• Decorative quilting
• Visible topstitching
• Accent stitching

40 Weight

One of the most versatile thread weights.

Excellent for:

• Machine embroidery
• Decorative stitching
• General quilting
• Many everyday sewing projects

It's a favorite because it balances strength with beautiful stitch definition.

50 Weight

Often considered the workhorse of quilting.

Ideal for:

• Piecing quilts
• General sewing
• Quilting
• Everyday cotton projects

Because it's finer than 40 WT, it blends beautifully into seams while creating strong, balanced stitches.

60 Weight

A fine thread commonly used for:

• Fine machine embroidery
• Delicate lettering
• Detail stitching
• Lightweight fabrics

Its fine size helps create crisp detail while reducing bulk.

80 Weight

An ultra-fine thread designed for projects where you want the thread to be as invisible as possible.

Ideal for:

• Bobbin thread
• English paper piecing
• Appliqué
• Heirloom sewing
• Micro quilting
• Fine detail work

Because it is so fine, 80 WT thread creates smooth seams with very little bulk and allows intricate stitching without adding unnecessary thickness.

Which Weight Should You Buy?

If you're just getting started, don't worry about owning every thread weight.

A quality 40 WT and 50 WT thread will handle the vast majority of sewing and quilting projects.

As your skills grow, you'll naturally discover when specialty weights like 12 WT, 60 WT, and 80 WT make sense.

There's no rush.

Common Beginner Mistake

Many beginners assume a thicker thread is always stronger.

That's not necessarily true.

Different thread weights are designed for different purposes.

The best weight depends on the look you want and the project you're making—not simply the thickness of the thread.

Quick Tips

• Smaller number = thicker thread.
• Larger number = finer thread.
• 40 WT is excellent for embroidery and many decorative projects.
• 50 WT is a favorite for piecing, quilting, and everyday sewing.
• 60 WT is ideal for fine embroidery and delicate detail work.
• 80 WT is perfect when you want minimal bulk and nearly invisible stitching.
• Start with a few versatile thread weights before buying specialty threads.
• Let your project guide your choice.

Remember This

Don't start by asking,

"What thread weight should I buy?"

Start by asking,

"What am I making?"

Once you know your project, choosing the right thread weight becomes much easier.

Continue Learning

You've now learned how to:

• Choose the right thread
• Understand cotton vs. polyester
• Select the appropriate thread weight

You're ready to explore our thread collections and choose with confidence.

➡️ Browse Thread Collections