Yarn Burn Test. Identify Your Yarn Fibers with Ease!

Picture with flames and caption Yarn burning test

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Learn how to identify different yarn fibers – synthetic, plant-based, or animal – with this simple yet revealing technique – yarn burn test.

Welcome to the fascinating world of yarn burn tests!

Have you ever been curious about how to identify different yarn fibers through burning a small sample? Whether you’re an experienced yarn enthusiast or a novice, this blog post is here to demystify the art of yarn burn tests.

We’ll delve into the unique burn characteristics of various fibers, including cotton, silk, wool, and synthetic yarns, and reveal the valuable insights they offer when exposed to flame. To enhance your understanding, I have also included original video examples for a visual demonstration.

So, let’s unlock the secrets of identifying yarn by utilizing this intriguing technique!

The burn test is a straightforward yet somewhat subjective method that relies on understanding how different fibers burn.

When conducting a burn test, it’s important to observe several factors, such as

  1. Whether the fibers melt or burn
  2. If they shrink away from the flame
  3. What odor the fumes emit, the characteristics of any smoke produced
  4. Appearance of the residue left behind by the burned fibers.

These observations can provide valuable clues in identifying the type of fiber being tested.

Precaution before burn tests

When conducting a burn test for yarn, it’s important to take proper precautions to ensure safety.

Here are some precautions to consider:

  1. Conduct the burn test in a well-ventilated area or under a fume hood to avoid inhaling any fumes produced during the test.
  2. It is safer to use long matches or a lighter for the burn test.
  3. Use a small sample of yarn for the burn test and avoid using yarn that is currently attached to a larger project, as burning yarn may cause damage.
  4. Keep a fire extinguisher, water, or a fire-resistant material like a ceramic plate nearby to extinguish any flames that may occur during the test.
  5. To prevent burns, use suitable tools like long-nosed pliers or tweezers to hold the yarn during the burn test, instead of using your fingers.
  6. Be cautious of hot ashes or residues produced during the burn test, as they may cause burns or fire hazards. Allow the yarn to cool completely before handling the ashes or residues.
  7. Follow local fire safety regulations and guidelines when conducting the burn test, and avoid conducting the test near flammable materials or in an unsafe environment.
  8. If you have any respiratory conditions or sensitivities, consider wearing a mask or conducting the burn test in a well-ventilated area with proper ventilation

Cotton burn test result

Cotton fiber:

  1. Typically burns easily with a steady flame, does not melt.
  2. Bright yellow flame, yellow-orange afterglow
  3. Smells like burning paper or leaves
  4. Leaves behind a fine ash. The ash is usually light gray or white and crumbles easily when touched.

Linen burn test

  1. Burns similar to cotton, but not as quickly. Flame goes out a little faster
  2. The ash left behind is usually light gray or white
  3. Smells like burning paper or leaves
  4. No hard bead-like residue
Linen yarn burn test results

Wool burn test results

  1. Ignites slowly.
  2. Burns with a self-extinguishing flame that is often accompanied by a smell of burning hair or feathers.
  3. It shrinks from the flame, does not melt.
  4. Stops burning when it is away from the flame
  5. The ash left behind is usually dark, brittle, and forms a small bead-like residue
Watch a short video to see how the wool fiber burns in action!


  1. Difficult to ignite, curls away from fire
  2. Burns with a slow, steady flame
  3. Stops burning when it is away from the flame may shrink
  4. Smell similar to burning hair or feathers
  5. The ash from the burn is dark, gritty, fine powder.

Synthetic yarns (acrylic, polyester, polypropylene or nylon)

  1. Shrinks away from fire.
  2. May produce black smoke with a strong, chemical odor.
  3. They don’t produce ash and don’t burn. They melt. Might drip (be aware of it when burning)
  4. What’s left behind is usually dark, hard, and may form a plastic-like residue.


  1. Catches fire quickly
  2. Burns with a steady, yellowish flame that is not too fast or too slow.
  3. Jute maintains its structure during burning
  4. Light grey ash
  5. Natural, earthy smell when burned, which is often described as similar to burning wood or vegetation.


  1. Catch fire quickly and rapidly burn up (even faster than cotton) with a yellow flame.
  2. Burning paper smell
  3. Leave a small amount of light gray ash

Blended yarn fibers

We need to remember that the burn test is not always definitive and can have limitations, as blending some yarns or fabrics or treating them with chemicals can alter their burn characteristics.

When dealing with blended yarns, the burn test can provide insights into the dominant fiber content, as the combustion characteristics of different fibers may vary.

However, accurately determining the percentage of each fiber in the blend is not always possible. When dealing with plied yarns made of multiple strands, you can try separating the strands and conducting burn tests on each strand individually, as sometimes the plied strands may be composed of different fibers. 

It’s important to note that, in most cases, all the fibers in a blend are carded together before spinning (like in this wool/acrylic fiber burn test, where separating strands didn’t work).

What is carded yarn?

“Carding is a mechanical technique that untangles, cleans, and blends fibers to create a continuous web or sliver that is ready for further processing.”

50% wool/50% acrylic yarn burn test

I had wool/acrylic yarn blend in my stash, and I tried to burn it and see what will happen. It was carded yarn mix.

Here are the key characteristics:

  1. Melting and/or burning: The blend may melt or burn with a combination of plastic-like and natural fiber smells.

  2. Shrinkage: The wool portion may shrink when exposed to flame due to its natural tendency to do so.

  3. Odor: The burning yarn may emit a mix of synthetic and natural fiber odors.

  4. Smoke: The smoke produced during the burn test may have characteristics of both synthetic and natural fibers.

  5. Residue: The residue after burning may show remnants of melted acrylic and charred wool fibers, indicating a blend of synthetic and natural fiber properties

Another way to identify a blend is by inspecting the colors in the strand. If there are slight variations in color shades within the same strand, it’s likely a blend of multiple fibers, as different fibers may take dyes differently, resulting in variation.


In conclusion, the burn test is a valuable tool for identifying yarn fibers and unraveling the secrets hidden within your stash. By understanding how different fibers behave when burned, you can gain insights into the composition of your yarn and make informed decisions for your projects. We hope this blog post has been informative and enjoyable for you.

If you’re hungry for more yarn-related knowledge, be sure to check out an article about cotton yarn.

Happy yarn burning and crafting!

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