How to do a Burn Test to Identify Fabric

How to do a Burn Test to Identify Fabric

Have you ever wondered if that mystery fabric in your stash is 100% wool? Or whether the delightfully flowy deadstock you just bought is viscose or polyester? Burn testing is one of the most accurate ways to figure out the fibre contents of your fabric at home and it's something we do all the time here at Core Fabrics whenever we are trying to verify the fibre composition from our deadstock suppliers. It's a great skill to learn and we'll show you how to become your very own fabric detective!

What is a Fabric Burn Test?

Different types of fibres burn differently - it's true! Cellulose, animal and synthetic fibres all respond differently to flame, and analyzing how they respond to flame (from speed to smell and type of ash) will help you identify the specific type of fibre.

We are going to walk you through how to conduct a burn test at home, but please use good common sense and be careful – fire is dangerous! 

Fabric Burn Test | Core Fabrics

Step 1: Preparation

To prepare for your burn test, you will need:

  • A flame source. We use a lighter, but you can also use a candle if you plan on testing multiple fabrics so you don’t have to keep striking your lighter.
  • Tweezers. Some fabrics can burn unexpectedly quickly, and tweezers ensure your fingers stay safe from the flames.
  • A fireproof dish. Dropping flaming fabric onto a flammable surface – or even worse, your fabric stash – could spell disaster. It’s best to have a ceramic, glass, or other fireproof dish under your burn testing area. It's also a good idea to conduct burn tests over the sink, just in case.
  • A glass of water. Just for extra safety, I like to keep a glass of water nearby to extinguish any flames in the case they get out of control.
  • A ventilated area. Burn tests should be done in a space with plenty of ventilation. Synthetic fibres can give off harmful fumes, and burning fabric in general can smoke up a room.
  • The Core Fabrics burn test chart, which will help you identify your fabric - get it below!
  • Your fabric swatches! You’ll need some strips of the fabric you wish to test. I recommend pieces that are about 2 x 3 inches, but really any size that is large enough to hold onto with your tweezers while leaving plenty to be exposed to the flame is good.

Download the Burn Test Chart

Step 2: Burn Testing Fabric

Once you’re all set up in a ventilated area, it’s time for the exciting part! To begin, light your candle, or hold your lighter in one hand and your fabric in tweezers in the other hand. As you bring the fabric and the flame together, note how the fabric reacts. Does it curl away from the flame? Does it catch immediately, or take a while to light?

Once your fabric does light, look at the flames. Are the flames bright? Is it burning quickly, or does it smolder out? Does the fabric simply melt as the flames sputter along? What smell does the smoke give off?

When your fabric is finished burning, examine the ashes. What shape are they? They may ball up or be powdery. Do they fall apart when you touch them, or do they stay hard? Are they congealed onto the fabric? Please be careful when examining the ashes, as they may still be hot or contain embers.

Step 3: Drawing Conclusions

Once you’ve gathered information about the way your fabric has burned, you can begin to deduce what kind of fabric you have. Fabrics tend to fall into three categories: animal fibres (such as wool and silk), cellulose fibres (such as cotton, linen, and viscose), and synthetic fibres (such as acrylic or polyester).

Animal fibres are slow to catch, and do not continue burning for long once removed from the flame. The ash tends to bead up, but crush easily when touched. There will be the scent of burnt hair in the room.

Cellulose fibres catch quickly, burn bright, and leave behind powdery ashes and a burnt paper scent.

Synthetic fibres behave much like plastic when exposed to flame. They curl away and melt. Some even drip down or form long, hard strings. Polyester and nylon smell sweet when burnt, like chemical marshmallows, while acetate and acrylic develop more of a vinegar scent.

Fabric Blends

Sometimes fabrics are made up of more than one fibre, which will make them a little harder to identify; but by looking closely as the fabric burns, you will be able to pick out various traits that will give you an idea of the contents of the blend. You'll notice the superwash wool burns similarly to the wool, but the ashes curl inward and are slightly melted. This lets us know that while the fabric is mostly wool, it has likely been coated with a synthetic to make it machine washable.

It can also be helpful to pay attention to the traits of your fabric outside of the burn test as well. For example, the cotton-poly blend we tried has black, powdery ashes, but it retains a little more structure when burned than the 100% cotton, and it smells faintly of chemicals alongside the burning paper smell you would expect from cotton. But beyond this, it has quite a bit of give and stretch for the way it is woven, meaning that it is very likely there is a touch of synthetic fibre blended in to assist with recovery. 

Video Tutorial

Need more help visualizing? We've got you covered with this helpful video where we show you the burn tests of a wide variety of fabrics!

Burn Test Infographic

To help you identify your fabrics easily, we also created this easy to follow infographic! Save it to Pinterest for later reference.

Burn Test Flow Chart | Core Fabrics


We hope this helps you to identify all those mystery fabrics in your stash!