Tips for Testing Fabric Content

testing fabric content

Here's a quick video on testing fabric content.  Before we get started, please be careful if trying this at home.

In the video, I've used relatively large samples so you can easily see what's happening.  I'm also in a controlled environment and using fabrics I'm confident have not been soaked in anything or that may be overly flammable.  If you're doing this yourself, use small samples and be very careful.  Adult supervision is essential.

Many people are unable to easily detect the presence of synthetic materials like polyester in fabrics.  Milling and weaving processes have been so refined and material properties so improved that it is often next to impossible to tell the difference between all-natural fabrics and synthetics –until it's too late sometimes and you either already bought the fabric or have made something you really wanted to be natural and it turns out synthetic.

I often go to large fabric stores and markets and am faced with a dizzying array of fabrics.  In Asia where I used to live and also here in Chile where I live now, it is often risky to believe what a vendor tells you about the fabric content.  I've found the only reliable way of testing fabric content is to do this quick test myself.  I've found that vendors often don't want me to do it since they realize I will probably learn the true fabric content and be unhappy with it, but I insist in any case.  I've never been sorry about testing fabric content before buying an important piece of fabric.  You won't be sorry either.

By doing a small burn test you can quite easily tell the difference between common natural fibers like cotton or silk and fabrics containing polyester fibers.  In a nutshell, natural fibers will burn completely and leave a light ash.  Polyesters, which are essentially plastic, will melt and burn with black smoke and smell like burning plastic.  You'll easily smell the difference.

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What about wool fabrics?

This test will not work on wool fabric which resists burning naturally.  Wool is often used for fire blankets and in cinema wall curtains and theatre drapes for these reasons.

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33 Responses to Tips for Testing Fabric Content

  1. Vanessa S, says:

    Fantastic informative video, thanks for that very useful information.

  2. Charleen says:

    Great presentation on fabric identification and your comments about vendors not wanting you to test resonates with my experience in Africa and Madagascar.

  3. Anne says:

    very good demonstration. Burning cotton smells like burning grass, and wool will smell like burnt hair, and as you said burning Polly smells like burnt plastic.

    • tmana says:

      You don’t need to burn wool to smell it. Hold the end of the bolt in your hand long enough to do a wrinkle test (several seconds), then bring that corner up to your nose.

  4. berlingueau says:

    Super. I often buy fabrics in second hand stores so I do not know what it is made of. Thank you.

  5. Betty Hankinson says:

    Excellent. Thank you so much. I’ve often wondered how these would react.

  6. Barb says:

    Thanks for this nice presentation. It is interesting to see how the various fabrics react to flame.

  7. Niki says:

    Very useful thank you. I test my yarn for wool content by soaking a piece of it in acetone – If it dissolves completely, it’s wool but, l wasn’t sure what to do with fabric.

    • Mayra at So Sew Easy says:

      HI Niki, thank you so much for your comment. I never heard of such a test. I will try it and add it to the article.

      • Niki Prattley says:

        You’re most welcome. Happy to pass it on. I learnt it from someone l was buying secondhand woolen yarn from.

    • tmana says:

      Bleach will also dissolve animal fibers (wool and silk) over the course of several hours. Bleach will also turn white versions of these fibers a deep yellow before dissolving them.

  8. Reen Romano says:

    Thank you for the demonstration. What happens with cotton/poly blend?

  9. Susan says:

    Thank you for the video showing how this is done. I have been wanting to check some fabric I was given, but I had only heard about the burn test and wasn’t sure how to go about it.

  10. Anne says:

    Burning polyester leaves a hard bead as well as smelling like burnt plastic. i have encountered the burnt plastic smell in what I thought were coated fibers or perhaps a fiber finish when the predominant smell was burnt paper [rayon fiber I’d guess.

  11. Roberta says:

    Thank you for your explanation. I have heard about the burn test but never seen it done before.

  12. LoAnn Trowbridge says:

    I have recently used this test, as I was making several microwave bowl potholders. All but one of the materials I had picked was 100% cotton. The batting of course also has to be 100% cotton (I use Wrap and Zap by Pellon).

  13. Laura Marston says:

    I would love to make your hoodie from this fabric!

  14. Laura Marston says:

    I f you do the burn test on wool using pulled threads and on a scrap of silk both will smell like burning hair!

  15. Theresa Bush says:

    I was at a small, but overflowing, fabric shop in Atlanta and found a tube of fabric with no label. I brought it to the owner, who was at the cutting table. Unsure himself, he cut a small piece off of a corner, produced a lighter from his pocket, and then proceeded to light the piece on fire. Afterwards, he told me what it was. I was fascinated and in awe.

  16. Claudia W says:

    So interesting! Thank you for sharing the information.

  17. Edith Richards says:

    This is very interesting. Thanks so much for sharing. I’m going to give this a try on some of the fabric I have in my stash that I’ve been wondering about.

  18. Rosalba D'Agostino says:

    Thank you. That was fascinating.

  19. Mona says:

    I love the video. It is very informative.

  20. Sharon Clampitt says:

    Reminds me of grad school! We were required to take a class on these techniques! lol (Home Ec major…back in the 70’s)

  21. Maria G says:

    Great Tips, thanks for the videos too. Thanks for sharing.

  22. Kaye Shears says:

    Informative and also a great way to find fabrics to be sure of future safety.

  23. Monica Curry says:

    Very informative video. I occasionally pick up fabrics at thrifts stores and can be easily fooled. Thanks for sharing.

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