An Ultimate Guide to Sewing Thread

In this article, you will learn the least you need to know about sewing machine thread fiber content; thread weight; choosing high-quality thread; choosing the appropriate thread colour for your project; checking thread quality; testing thread strength; and storing thread.

The human body has its essential nutrient requirements: high-quality protein, healthy fats, leafy, green veggies, vitamins, and minerals.

Well, thread (and sewing machine needles) are like essential nutrients for your sewing machine.

Just as many of us try not to feed junk food to our most prized possession — our body! Well, don’t feed junk to your sewing machine.

Bottom line:

Your sewing machine will perform best when it is fed quality thread (and the appropriate sewing machine needle).

So make it your business to check each spool of thread BEFORE you thread your sewing machine.

In this post, we are going to cover a lot of information. You will learn:

  • About thread fiber content
  • About thread weight
  • How to choose the best thread colour for your project
  • How to determine how much thread your project will require
  • How to check if the thread is colourfast
  • How to store your thread
  • How to buy quality thread

WHEW! That’s a lot! So let’s get started with a couple of important rules…

Thread Rules

Rule #1: ALWAYS use strong, high-quality thread!

Rule #2: Match your thread size to your needle size to avoid any nonsense! For example, the thicker your thread, the thicker the shaft and the eye of your needle needs to be.

Rule #3: Ideally, you want to choose a thread fiber that closely matches the fiber of your fashion fabric. For example, you would choose 100% cotton or cotton-polyester thread when sewing cotton or linen; silk thread when sewing silks and woolens; and polyester thread when sewing synthetics.

However, for most general sewing or if you want to keep things ultra simple, I think you’ll do just fine if you choose 100% polyester or cotton-covered polyester thread.

Thread Fiber Content

Fiber content is probably the most important consideration when choosing a sewing machine thread for your fabric.

The ideal all-purpose thread is smooth and strong with just a bit of stretch.

Here’s the thing…

A high-quality thread produces less lint. And this is important because an excessive buildup of lint and fuzz will bring your sewing machine to a grinding halt!

Now that you understand what makes a quality thread and why it is important, here is a quick rundown on the various thread types you are likely to use when constructing garments…

100% Cotton Thread

Cotton thread is strong and heat resistant. But it has no stretch (aka elasticity), which could mean popped seams. It works best for fabrics made of 100% cotton or linen that require you to press at very high temperatures.

When a cotton thread is mercerized, the thread becomes stronger and has a nice sheen.

100% Polyester Thread

Ultimate Guide to Sewing Thread

A 100% polyester thread is smooth, super strong  and elastic. This elasticity means less likelihood of popped seams, yay!

It also doesn’t shrink or fade.

But it can be scorched when pressed at very high temperatures.

This thread is an excellent choice for almost all fabrics!

Cotton-Covered Polyester Thread

This hybrid is an all-purpose thread that gives you the best of 100% cotton and 100% polyester. And it has all of the same qualities as 100% polyester thread.

It has a polyester core that is wrapped in a cotton exterior that is both durable and heat resistant.

Heavy Duty Thread

This thread is generally not suitable for garment construction. It is designed to be used with upholstery weight fabrics.

Silk Thread

Silk thread is soft but strong, has elasticity, and has a gorgeous luster. Because it is fine, it does not get knotty or leave unsightly holes or lint impressions in delicate fabrics.

However, it is best reserved for hand basting (rather than general construction) or for use with delicate fabrics.

And because of its luster, silk thread is also puuurfect for decorative stitching.

But you do have to keep this in mind…

If you bleach a garment made with silk thread, the silk thread can be damaged.

Elastic Thread

Ultimate Guide to Sewing Thread

Elastic thread is a specialty thread used for shirring. Shirring is a technique that makes the most lovely summer dresses.

Basically, begin by hand winding the elastic thread onto an empty bobbin.

Then, thread your machine with regular thread.

And finally, draw up the elastic thread on the bobbin as usual.

Now, you’re ready to make like a magician… I can’t wait until you try this technique!

Invisible Thread

Ultimate Guide to Sewing Thread

Invisible thread is a transparent thread that comes in clear and smoke. It is very fine and soft. And it will blend with any fabric.

Metallic Thread

Ultimate Guide to Sewing Thread

Metallic thread is a fun option for decorative stitching. You will need a special metallic sewing machine needle to avoid shedding and breakage of this delicate thread.

Also, avoid applying high heat.

Rayon Thread

Ultimate Guide to Sewing Thread

Rayon thread has an incredible sheen and comes in saturated, swoon-worthy colours.

While this is a truly lovely thread, there are a few things you should know…

  • It is delicate, so you can’t use it on construction seams.
  • It is often not colourfast.
  • And it is freaking expensive.

But it would make for some gorgeous decorative stitching.

Topstitching Thread

Topstitching thread is strong and thick for those times when you want a bold finish.

Ultimate Guide to Sewing Thread

And it is a great choice for decorative finishes and sewing on buttons that don’t fall easily.

But here’s the thing…

It must be used with a specialty topstitching sewing machine needle.

Variegated Thread

Ultimate Guide to Sewing Thread


I think you’d agree that this is one pretty spool of thread!

Variegated thread varies in colour along the strand and is another fun option for decorative stitching.

In the image above, the spool is not only variegated but also rayon.

Thread Weight

After fiber content, the next most important characteristic to consider is the weight. Yes, thread has weight.

Thread weight is designated like this: 50/3. The 50 indicates thread weight and 3 tell us how many yarns (or plies) make up the strand.

Here’s what you need to take away…

The tension on home sewing machines is usually set 4 at the factory. This will produce balanced stitching when sewing with 50/3 thread.

And all-purpose threads have a thread weight between 40 and 50, which is just right for light- and medium-weight fabrics.

RELATED: Thread Mastery: A Guide to Understanding Thread (this is late-night reading!)

Thread Colour Matters

Next, let’s start with the most obvious choice: Colours.

These are four basic colours that I always have in my sewing space:

Ultimate Guide to Sewing Thread

These are the four colours should be in every dressmaker’s thread collection: Black, White, Eggshell, and Slate.

When you choose colours for your project, choose a thread that takes a backstage seat by disappearing into the fabric.

White, beige and black can take you a long way. But they cannot take you all the way. There will come a time when you need other colours.

However, if you’re like me and are either frugal and/or a minimalist, you don’t want your thread supply to overflow with a rainbow of colours.

A gray or slate coloured thread can be a godsend. The beauty of gray or slate is that it is a colour that simply doesn’t mind being a wallflower, blending brilliantly into most prints.

Ultimate Guide to Sewing Thread

If a time should come when you need to buy a nonbasic colour for a project, simply hold the thread against your fabric. It should blend in and almost disappear.

And If you can’t find just the right shade and just want to begin already, choose a colour that is a shade darker than the dominant color in your fabric.

Got it?!

How Much Thread Do You Need

After colour, the next consideration is naturally how much thread will you need.

How much thread you need will depend on the size of your project.

Nothing is more frustrating than being in the groove of sewing and running out of thread in the middle of a project. So I think it makes sense and is budget-wise to buy large spools of the four basic colours: white, beige, black, and gray.

Also, keep in mind that those tiny spools of thread are often spent after you’ve wound ONE bobbin.

How to Check Thread Quality

By now you know how important thread quality is!

To check thread quality…

Ultimate Guide to Sewing Thread

Just cut off a length of thread and hold it to a bright light and look at the strand. Or, you could use a magnifying glass with a light like the Mighty Bright magnifying glass in the image above.

Carefully, inspect the strand. It should be mostly smooth, rather than a hot, frizzy, linty mess!

Fraying and frizziness mean EXCESS lint build up in your bobbin case and sewing machine. And excess lint will gunk up your machine and even bring it to its knees quicker than you can say “cold-hearted snake!”

Bottom line:

If the thread is fraying or feels rough, please for the love of your sewing machine and if you want a stress free sewing experience, chuck it!

How to Test Thread Strength

Just like we’ve been aging since we make an entrance into life, thread ages too.

Please don’t go thrifting and buy vintage thread to sew with. Just. Don’t.

Because sewing is a labor of love and time, why would you want to put all that love and time into something that won’t stand the test of time?


And it is good practice to test the strength of ANY spool of thread before you use it in your project. Yes, this applies even to “new” thread.

To test how strong your thread is…

  1. Cut off a length of thread.
  2. Hold an end in each hand.
  3. Now, pull firmly in opposite directions.

It should not snap. If it snaps, it is past its expiration date. Chuck it!

Or, keep it for basting. But do not under any circumstances use it for garment construction unless you don’t mind busting a seam in public.

Is Your Thread Colour Fast?

Some threads are not colorfast.

Ultimate Guide to Sewing Thread

To test if your thread is a bleeder…

  1. Lay a clean sheet of white paper towel on a table.
  2. Snip off a short length of the thread in question.
  3. Wet it good and place it on a sheet of paper towel.

Now assess. Did it bleed?

How to Store Sewing Thread

So simple.

Store thread in drawers or covered boxes protected from dust and sunlight!

How to Organize Your Sewing Tools & Supplies

High-Quality Sewing Thread

Guterman’s Sew-All Thread

Guterman’s Thread originated in Germany. And it is generally my thread of choice.

Ultimate Guide to Sewing Thread

It is cross-wound thread that is strong and does not shed.

And I think the thread is quite pretty on the spool. Superb.

There are many flavors (isn’t there always?!) of Guterman’s Thread. But for our purposes, the best choice is Gutterman’s Sew-All 100% Polyester Thread. Look for the cream-coloured spool.

Mettler Thread

Like Guterman’s, Mettler Thread is high-quality. It is super strong and simply beautiful to look at. That sheen is just captivating! (See the featured image at the top of this page.)

It is also a cross-wound thread that is twist balance, so it is less susceptible to getting into a knotty, tangled mess as it unravels from the spool!

Mettler comes in many flavors. But for our purposes, we would use the Mettler Metrosene Thread — it’s polyester.

This thread is not available locally for many of us, but it is so worth tracking down. (See my Resources page or do a Google search.)

Coats & Clark

Coats & Clark thread is readily available at most big box stores with a hobby/craft section and at local hobby/craft stores.

It is a stacked thread.

Ultimate Guide to Sewing Thread

But I simply cannot recommend its all-purpose thread! (This does not include the Eloflex (elastic) thread.)


Well, it just too darn linty for my tastes. And sewing machines loathe lint!

The End

Do NOT buy cheap thread. Your sewing machine performs better with high-quality thread. I love Gutterman’s and Mettler.

For general all-purpose sewing, buy 100%polyester thread or cotton covered polyester thread. Simple.

As for the essential thread colours, keep it stupid simple:

  • Black,
  • White,
  • Beige/Natural/Eggshell, and
  • Gray/Slate.

Finally, beware of old thread!

And remember…

Life is the ultimate red carpet event. Dress for it!