Let’s say that you received some unlabeled fabric from a friend and you want to use it for an upcoming sewing project. You need to know what the fabric is so that you know what you can use it for, but you’re unsure how to identify it. There are many ways to identify fabric, but a common way is by doing a fabric burn test.
Fabric burn tests are very effective in identifying fabric because fabrics react in different ways when they are burned. You can narrow down whether a fabric is natural or synthetic based on these reactions, and observe specific things to narrow down the fabric even more.
Keep reading to learn how to perform a burn test, how they are used to identify fibers, which ones catch fire easiest, and which ones are more resistant to fire. We’ve even included a chart that makes identifying fabrics even easier.
What is a Fabric Burn Test?
Burn tests can help with identifying what type of fabric an unknown material is. It involves setting a small piece of the fabric on fire and observing the characteristics that are produced while the fabric burns. Some examples would be seeing how quickly it burns, what the flame looks like, what smell is produced, what the smoke looks like, and what type of ash is produced.
Reasons for doing a burn test include knowing if that fabric will work for your particular project and how to care for it properly. In quilting, for example, cotton fabrics work best. Some fabrics may look and feel like cotton but are actually something else. Burn tests help you to identify what type of fiber a particular fabric is made of so that you know what to expect when using it and caring for your finished project.
How To Do A Burning Test
Before doing a fabric burn test, there are a few materials that you need to gather. You will need:
- Test fabric
- An ashtray or another flameproof container (something made of glass or metal)
- A long-reach lighter or long matches
- Water or fire extinguisher
There are some safety precautions to pay attention to when doing a burn test. Here are a few things to keep in mind:
- Burn tests should be done outside if possible.
- When doing a test outside, have some water on hand to quickly extinguish the fire.
- If you do a burn test inside, place your fireproof container inside a sink or to help contain the fire.
- Do not perform a burn test outside on a windy day or inside near a fan.
- Some fabrics produce hazardous odors, so perform the test in a well-ventilated area.
- Remove any flammable items that are nearby.
- Do not perform a burn test around children or pets.
- Do not touch the fabric, ashes, or drips with your bare hands.
- Use tweezers, as some fabrics can get extremely hot.
- Tie back long hair, roll up long sleeves, and avoid baggy clothing.
Steps to Perform a Burn Test
- Cut off a triangle or square piece of fabric that is one to two inches long.
- Using tweezers, put the fabric piece into your fireproof container.
- Use the long-reach lighter or match to set a corner of the fabric on fire.
- Pay attention to these characteristics as the piece burns.
- How quickly it burns
- Does it melt or drip?
- Smoke color
- After the fabric cools, pay attention to what the ashes look like. Common characteristics of ashes are soft, hard, brittle, or powdery. Ashes may also be different colors.
You can also examine how individual fibers react by unraveling another small piece of fabric. To do this:
- Pick up a few fibers with the tweezers and hold them over the fireproof container.
- Bring the flame near the fibers.
- Pay attention to how quickly the fibers catch fire, how they react to the fire, and if they start to melt.
To see a fabric burn test being performed, check out this video:
Limitations to Fabric Burn Tests
Burn tests are the most accurate way to identify fabrics, but there are some limitations. It’s easy to determine whether or not a fabric is natural or synthetic. But because natural fabrics share similar burn characteristics and so do synthetic fibers, it can be difficult to narrow down a particular fabric.
As an example, cotton is a commonly used fabric. But cotton, linen, and rayon are all natural fibers that are made of cellulose. They all share similar burn characteristics, such as smelling of burning leaves, producing gray smoke color, and leaving behind powdery ash. This can make it hard to differentiate between the three.
Synthetic fibers like polyester, nylon, spandex, and acrylic also share similar characteristics, such as melting, and producing dark smoke and strong odors. Then there are blended fabrics that may have characteristics of both depending on what percentage of fibers they contain.
To make a burn test most effective, you should perform it first on fabrics that you know what they are. If you know that a fabric is 100% cotton, do the burn test to see what happens when cotton is burned. Then do the same thing with linen, polyester, wool, and more. Make specific notes that you can refer back to later.
How Are Burn Tests Used to Identify Fibers?
Natural and synthetic fibers burn differently from each other. This section will cover some common natural and synthetic fibers and the burn characteristics that they will produce when doing a burn test.
Cotton / Hemp / Ramie
Cotton, hemp, and ramie are all natural and plant based. Because of this, their fibers are made of cellulose. Cellulose fibers will burn quickly and with a bright flame. When burning, these fabrics will produce a smell similar to that of burning wood, paper, or leaves. Smoke will be gray or white and the ash left behind will be soft.
Linen is also a cellulose fiber, but unlike cotton, hemp, and ramie, linen does not catch on fire as quickly. Other burn characteristics are similar to those of other cellulose fibers. Burning linen will smell like burning paper or leaves, and the smoke produced will be gray. Ash will be soft and powdery.
Wool / Cashmere / Alpaca
Wool, cashmere, and alpaca are all natural fabrics with fibers that come from an animal’s coat. Because of this, the fiber burns with a smell similar to that of human hair burning. These fibers do not catch fire easily because they are made up of protein. If they do catch fire, the fibers will burn slowly, sizzle, or curl away from the flame. Dark gray or black smoke will be produced. The ash left behind will be hard.
Like wool, silk fibers are made of protein. This means that silk will burn slowly. The fibers will also curl away from the flame. When it is burning, silk will smell of burned hair or feathers. It doesn’t produce much smoke, but leaves behind dark colored, powdery ash. Removing the flame will cause the silk fibers to self-extinguish.
Nylon is a synthetic fabric that is made from petroleum. Because of this, nylon fibers burn very quickly and leave behind hard, gray beads that are similar to plastic. Nylon leaves behind an odor that smells like celery and the fumes that are left behind are toxic and hazardous.
Polyester is another synthetic fabric. It is made mostly of petroleum and coal, so it burns with characters similar to those of nylon. Being made of petroleum causes it to burn quickly and leave behind hard, dark beads. Black smoke and a chemical odor are produced. The fumes that are produced are hazardous.
Rayon / Tencel
Like cotton, rayon and tencel are cellulose fibers that catch fire easily and burn quickly. Burning these fabrics will produce a large flame and the fabrics may produce a glow after the flame is extinguished. When rayon and tencel are burning, they produce hazardous fumes and an odor that smells like burning leaves. It leaves behind a gray, powdery ash.
Spandex is a synthetic fiber and shares characteristics similar to those of polyester and nylon. The chemicals that Spandex is made of means that the fiber burns quickly and will continue to burn after the flame is removed. Dark or black smoke is produced and may be toxic.
Acrylic / Modacrylic
Acrylic and modacrylic are synthetic and made from petroleum and natural gas. They don’t catch fire easily, but once they do, they burn very quickly and the flame may sputter. The flame is really hot, causing the fabric to melt and drip. A fishy odor is produced, as well as hazardous black smoke and fumes.
Acetate is a protein fiber that will burn easily and start to melt and drip. When burned, acetate leaves behind a bead that is hard. It smells like vinegar or pepper and produces black smoke that is hazardous, but doesn’t leave behind ash.
These two fabrics are synthetic and share characteristics of polyester when burned. Olefin and polyolefin burn quickly, produce a tar-like odor and leave behind a hard, plastic-like bead. Dark, hazardous smoke is produced.
What Fabrics Catch Fire Easily?
Natural cellulose fibers such as cotton, hemp, and rayon catch fire the easiest and burn really quickly. Some synthetic fibers that are derived from natural gas don’t necessarily catch fire easily, but they burn very quickly if they do catch on fire.
On the other hand, there are some fabrics that don’t catch fire as easily or are more resistant to fire. Protein-based fibers, such as wool and cashmere are more fire-resistant and slow-burning. In addition, synthetic fabrics like polyester and nylon are more fire-resistant because it takes incredibly hot flame temperatures for them to burn. Some fabrics are even treated to be flame-resistant.
What Fabric Material Burns the Fastest?
The material that a fabric is made of has the biggest effect on how quickly that fabric burns. Some materials are more flammable than others. Although polyester and similar fabrics don’t catch on fire easily, when they do catch on fire they burn the fastest. This is because they are made of petroleum products, which are highly flammable.
Cotton and other plant-based fibers also burn easily because cellulose is similar to wood. While cotton burns easily, it may not burn as quickly as polyester. Polyester/cotton blends burn very quickly since they are made of both polyester and cotton, but the percentage of polyester and cotton determines how fast a blend will actually burn.
What Fabric Materials Are Bad to Burn?
Synthetic materials are bad to burn. These include polyester, nylon, acrylic, modacrylic, olefin, and polyolefin. The fumes and smoke that are produced by burning these are hazardous and may even be toxic. They also tend to smell really bad considering that they are made of chemicals like petroleum.
These materials will also melt and drip when exposed to flame. The drippings will get extremely hot and can cause severe burns if they are touched.
What Material Does Not Burn in Fire?
There are very few materials that are completely fire-resistant. Kevlar is a name-brand material that is the most heat and fire-resistant because it is engineered to be that way. Kevlar is made of a type of fiber called a polyamide. These kinds of fibers are fire-resistant.
Another name-brand material is Nomex. Nomex is made of a thickly-woven fibers, so while it will catch on fire when it comes into contact with a flame, it will stop burning when the flame is removed. The flame won’t be enough to penetrate through the thick fibers.
Any fabric can be made to be fire-resistant by treating it with a fire-retardant. Fire-retardants work by slowing down the reaction that causes fires to ignite. Since cotton and polyester are found in a lot of household fabrics, fire-retardants are great for using on these fabrics, especially if they are located near a fireplace.
Fabric Burn Test Chart
Burn test charts are used as a quick and easy reference to identify different materials. The charts give information about the characteristics that are expressed when each material is burned. This helps you to be able to tell if a material is synthetic or natural so that you can narrow down and eliminate certain ones. We have provided a chart here for your quick reference.
|Fiber Type||Flame||Odor Produced||Ash|
|Cotton/ Hemp / Ramie
|Burns quickly and easily. Will continue to burn or glow after flame is removed.||Burning wood, paper, or leaves||White or gray, soft, and powdery|
|Not as quick to start burning, but will burn easily and continue to burn when flame is removed.||Burning paper||Gray, soft, and powdery|
|Wool/ Cashmere / Alpaca
|Doesn’t catch fire easily. Will sizzle and burn slowly when it does. Fibers may curl away from flame and extinguish when removed.||Burning hair||Hard black bead that can be crushed to powder|
|Doesn’t catch fire easily. Will sizzle and burn slowly when it does. Fibers may curl away from flame and extinguish when removed.||Burning feathers||Dark bead that can be crushed to powdery ash|
|Will melt in droplets instead of lighting on fire.||Celery||Hard, gray beads|
|Will melt instead of lighting on fire.||Sweet chemical smell||Hard, dark or black beads|
|Rayon / Tencel
|Quick to start burning. Will continue to burn.||Burning paper||Gray, powdery|
|Will melt instead of lighting on fire.||Chemical smell||Black, sticky|
|Acrylic / Modacrylic
|Will melt instead of lighting on fire.||Fishy||Hard but brittle beads|
|Will melt instead of lighting on fire.||Vinegar||Dark bead|
|Olefin / Polyolefin
|Will melt instead of lighting on fire.||Tar / Asphalt||Hard tan or brown bead|
We hope you found this article helpful to identify your unknown fabric. Natural and synthetic fabrics have different reactions when burned. Carefully observing these reactions and comparing them to the above chart will help make identification easier. If you enjoyed this article, be sure to share it with others and leave a comment. Thanks for reading!