How to Tell If Your Thread Has Gone Bad

Aurifil Thread

Thread doesn’t last forever — that’s just the sad truth — so it’s important to know what’s safe to use and what needs to make its way to the trash can. Before you allow a new spool into your collection or pick up an old favorite, here’s what you should be looking for.


faded spool of thread


Light can cause thread to fade and weaken. If you notice it’s visibly faded, say goodbye or use it for a less important project.


Humidity is another enemy of our sweet spools. If you live in a very dry climate, it can cause your thread to become brittle. In a humid climate, thread can mold or become sticky.


Dust can also settle on spools. That means when you thread your machine, it gets pulled right into it the tension discs, and can bring your stitching to a screeching halt.

Make it last:

Proper storage is everything when it comes to preserving your thread. Keep it wound tightly to prevent tangling, and make sure it stays away from light and dust.

How to check for wear:

Broken Black Thread

Unspool a length of thread and give it a tug. If it breaks easily, it’s probably become too dry and brittle to use. If it’s hard to tell, do the same thing with a new spool of thread for comparison. It’ll be pretty clear which spools aren’t making the cut.

Can’t quite throw it away?

If your thread still has some life left in it (but not enough for an important project), put it to use in smaller jobs like tailor’s tacks, temporary basting or thread tracing. Just keep it away from the sewing machine.

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3 Responses to “How to Tell If Your Thread Has Gone Bad”


    How to tell if cotton is bad

  2. Victoria

    This may sound crazy but I have OCD so need to check this out. I have several old cross stitch kits (some may be up to 20 years old). Is there anything in the thread or canvas that would go “bad” or toxic?

  3. Lina gomez

    I want to learn more about my mother's athena 2000 sewing machine.