How to do a fabric burn test

What is a Fabric Burn test?

Hi creative mamas! Do you get confused and overwhelmed when you don’t know what kind of fabric or yarn you are really buying? Even worse, if you are always on the hunt for second hand fabric you will need to know how to do a fabric burn test.

How to do a fabric burn test

The thing is, second hand fabric doesn’t have any labels to identify what is what, so it can feel like you are always on the dark. 

I love my natural fibers (cotton, silk, linen, wool, hemp) so I use The Burn Test a lot to identify fibers and if you do it enough times you will start to recognize the different qualities straight away. So no one can ever fool you again!

Fabric identification Burn Test

Today one of my students showed me the lovely silk that she had bought overseas. The minute I saw the fabric I knew that it was not silk. I suggested to do The Burn Test straight away and it was quickly revealed that the silk that she thought she had bought was actually pure synthetic.

She was so sad, however after learning to do this test she felt very empowered and I am pretty sure that no one will ever be able to fool her again in the future 

When working with textile crafts and in particular natural dyeing it’s very important to know the difference between synthetic fibers and natural fibers. All natural dyeing techniques will work beautifully for natural fibers but will not work for synthetic fibers.

It can take a long time to develop the skills to differentiate a silk from a silky polyester for example, or a wool yarn from an acrylic yarn.

So let me show you a great way to quickly know what kind of fiber you are dealing with. It’s called the burn test.

Things you need to know before doing the fabric burn test

The fabric burn test must be done away from your kids, in a well ventilated area and away from flammable surfaces. I like using a ceramic plate or a damp wooden board. Make sure there is plenty of water around you and be sure to be next to the kitchen sink. Also make sure kids understand that this must never ever be done by them.

Watch this step by step video tutorial: How to do a fabric burn test

In this video tutorial I will show you what happens when you burn a 100% silk swatch and a 100% polyester swatch that was being sold as silk as well as 100% linen swatch. They both look very similar to the eye and to the touch so it can be quite tricky to tell the difference. That’s when the Burn Test comes in handy!

Video transcription of process:

Let’s get started:

Grab a piece of your chosen fabric

Get a lighter or matches. You can also use a pair of tweezers to hold the fabric, I like to use my hands.

Carefully light the match or lighter and hold it up against the edge of the fabric. How the fabric reacts will tell you what it’s made from.

Polyester Burn Test

In this first example I am burning the polyester fabric first and as you can see the fabric is actually melting when hit with the flame. There is no ash, rather it melts into a plastic edge which is hard and not easy to break.

Cotton Burn Test

When doing the same with the cotton and the linen, the fabric will burn fast and when removing the match the fabric will continue to burn. It will create ash and it will brake away when touched.

Wool yarn burn test

Lets see what happens with the yarns. I have 100 % wool yarn and a 100% acrylic yarn.

The wool yarn reacts like the silk and the linen. It burns and then the ash breaks away when touched. On the contrary, the acrylic yarn reacts by melting into a hard plastic bead.

You are now ready to identify natural fibers from synthetic ones! Gather a few natural fibers such as silk and wool scraps or yarn and you are ready to start experimenting with Eco dyeing techniques!

After you have identified the natural fibers from the synthetic ones you are ready to start experimenting with natural dyeing techniques. For best results start with silk and wool fabric or yarn.

Check out these amazing natural dyeing tutorials:

How to dye beautiful pinks with Avocado dyes

How to dye fabric with onion skins

Fabric Printing With Natural Dyes

Natural Bundle Dyeing, make your own DIY scarf

The Beginners Guide to Solar Dyeing

How to Eco Print on Paper

6 thoughts on “How to do a fabric burn test”

  1. When using black tea for dying can any black tea do the trick?
    Also does the tea staining last on fabrics or does it eventually was out?
    Thank you so much for sharing all of your wonderful information.

    • Hi Pauline,
      thanks for your message. Any black tea will do, i use the cheap english breakfast variety and I get it in tea bags because it’s easy and less messy 🙂 Also as long as you follow the process outlined here the dye should stay. To make it even more durable I suggest that you mordant the scour and fabric and then the color is there to stay !!! Hope this helps but reach out with any other questions that you may have 🙂

  2. What happens to fabric that is a combination of two or more fibres on a burn test. I think I have sine socks that say 80%amd 20% elastin.

    • Hi Deborah, socks are usually a combination of elastane and that is ok 🙂 as long as the natural fiber is no less than 80% it has always worked great for me. Hope this helps! cheers


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