Sewing Thread Going Bad: What’s The Reason

Your sewing success is determined by the threads you use. Using thread that is too old can be dangerous, and cheap, low-quality threads are also not suitable for sewing.

Does Sewing Thread Go Bad?

To answer, yes. Thread deteriorates for the same reason that many other materials deteriorate exposure to the elements. Light, humidity, dust, and temperature are examples of these elements. Prolonged exposure to elemental extremes weakens the thread’s fibers, resulting in breakage.

A good quality thread manufactured today will last much longer than a thread manufactured 15 or 20 years ago. Even the best quality cotton thread from a generation ago did not have the advanced processing techniques available to us today, so it is probably best not to sew or quilt with old thread that is still available.

However, a high-quality cotton thread manufactured today will most likely be suitable for use in 40 or 50 years. The difference in longevity is due to advancements in spinning, dyeing, and twisting technology, as well as the evolution of better cotton plants through genetic engineering.

Cotton, as a natural fiber, will degrade over time. To see if the cotton threads you’ve been given are safe to use in your machine, hold about a one-foot section between both hands and pull them apart. If the thread snaps, it is safe to use.

The color of the polyester thread may fade over time due to exposure to sunlight, but there is no evidence that the thread deteriorates like cotton threads, so synthetic fibers will last longer.

How Long Does Thread Last?

Sewing thread eventually wears out. Quilting thread and piecing thread can last for 50 years or more. However, if the thread is not correctly saved, the time length decreases significantly. The thread should be stored away from direct sunlight because it can fade and weaken the fibers.

It can become sticky or too thick if stored in a humid environment, such as a garage or attic, for an extended period of time. Similarly, storing it in a very dry or cold climate can cause the fibers to become brittle and break.

In general, if you’ve purchased or own thread that is dusty, it’s a sign that it hasn’t been properly stored. Here are some additional indicators that the thread is still in good condition:

  • The thread’s durability (cheap versus a more high-quality thread)
  • The thread coating (a polyester thread will not deteriorate as quickly as a cotton thread)
  • The spool’s materials (plastic spools help threads last longer than wood or Styrofoam ones)
  • Date made (older threads were not made with the technology we have now, so they do not last as long as threads purchased new in a store today)

What Are Some Thread Longevity Factors?

People who collect vintage textiles, such as quilts and clothing, take care to keep them out of the sun, dirt, and abrasion. Important textiles are stored in dark, cool places and are rarely handled, even by gloved conservators.

Thread is a textile, so if it has not been properly stored, it may be ruined. Thread stored in a closet box will be in better condition (stronger and cleaner) than thread stored in the open on a thread rack near a window.

Natural fibers are susceptible to insect damage as well as dry rot or mildew, depending on humidity levels in the storage area. Furthermore, because they are not spun as well as modern core-spun threads or microfiber polyesters, dime-store polyester threads shed excess lint.

Should You Re-Use Or Discard Old Thread?

While your old thread may be suitable for use, think about the project for which it will be used. Don’t take chances with new fabric and thread.

Here are some suggestions for what to do with old threads:

  • It’s great for hand basting.
  • It’s great for decorative stitching.
  • Fill a Mason jar with spools to display on a table or library shelf.
  • Make use of old wooden spools in your crafting projects.
  • Don’t be so quick to toss out old threads.

How To Test Sewing Thread?

Even if you don’t have access to a modern engineering lab, you can still perform some standard thread checks.

Hold a length of thread taut in both hands. Slowly separate your hands (do not jerk) to see if the thread stretches and the fibers differ before the thread breaks. If that’s the case, the thread is dead. If you get a nice breeze (or you can’t damage it at all), you should be fine using the thread.

Long-staple polyester thread and cotton-wrapped polyester core threads will certainly last longer than 100 percent cotton in general.

How To Extend The Life Of Thread?

Though there is no way to make thread last forever, you can extend its life by storing it properly for years.

Here are some simple tips to keep your thread in top sewing condition for as long as possible:

  • Always wind your thread around the spool neatly.
  • Keep your thread in a container that separates the spools, protects the thread from settling dust, and keeps the thread away from light.
  • Keep your thread in a relatively stable humidity environment, such as the main part of your home.
  • Keep the thread at room temperature.

Related Questions

How do I know if my old thread is still valid?

Examine your ‘old’ threads. Hold one end of a 38-45cm piece of thread in each hand and pull until it breaks. It’s probably fine if you feel some resistance, but if it breaks easily, it’s time to say goodbye.

How do you keep the thread?

The thread should be stored in a container that keeps the spools separated and tangle-free, such as clear bins or thread boxes. Thread can also be stored in boxes or bins with small compartments or separators.

When Does A Thread Expire?

Yes! Thread has a shelf life, though it’s difficult to say how long it has. This question is frequently asked when someone inherits sewing supplies, including vintage thread. The vintage thread is noticeably fuzzier than others. That fuzz is going to clog up your machine.


In short, if stored properly, sewing thread can last for many years. Excessive dust, moisture, and sunlight, on the other hand, can ruin the thread.