Burn tests

Why would you set fire to your fabric?

You may have heard mention that a burn test will help to determine your fabric composition, but you’re not sure what you’re looking for when you burn your swatches.

Believe it or not, the flame, smoke and ash from burning a piece of fabric can tell you a lot about what it’s made of.

You’ll need to use your judgment and go by a few other cues as well, such as creasing, drape and handle of the fabric, but doing a little burn test can help you to determine what your fabric is made of if you still aren’t sure.

Burn tests are never going to be 100% accurate; so many fabrics are a blend of 2, 3 or more fibers. But it is going to give you an idea, and you can easily tell from a burn test if your fabric is a pure natural fiber or a synthetic.

Items you’ll need.

• A small piece cut off of your fabric approximately 1”x 1”, do not try to burn the edge of a large piece of cloth.
•   A pair of tweezers to hold the fabric
•   A fire resistant container- such as a foil pie dish or a ceramic/glass plate
•   A candle and matches or a lighter
•   Water, in case you need to extinguish the fire.

What to do.

• Set up everything in a well-ventilated area outside. Some fabric can produce hazardous smoke. You also don’t want to do this near a smoke alarm.
•   Light your candle and set fire to the piece of fabric, holding it with tweezers so you don’t burn yourself.
•   Drop it into your container and observe how it burns, take notice of how it smells.
•   Allow the piece to extinguish itself, let it cool down and then examine the ash
•   Crumble the ash with your fingers and observe how it crumbles and how it disintegrates.

Here’s a short video of us having fun, setting fire to some fabrics:

Here’s a brief breakdown of the most common fabrics, and how they will respond when burned:

Cotton           

• Natural cellulose fiber
• Burns readily, with a glowing edge, then chars
• Smells like burning paper
• Soft, powdery grey ash

Hemp, Linen

• Natural cellulose fiber
• Burns readily, then chars
• Smells like burning grass
• Soft, powdery grey ash

Silk

• Natural protein fiber
• Self extinguishing
• Odour of burning hair or feathers
• Forms a soft black bead that is easy to crush, it crumbles

Wool, mohair, cashmere.

• Natural protein fiber
• Self extinguishing
• Smells like burning hair or feathers
• Dark irregular ash

Viscose

• Man-made cellulose fiber
• Burns readily, then chars
• Smells like burning paper
• Soft, powdery grey ash

Acetate or triacetate

• Man-made protein fiber
• Burns and melts
• Odour of vinegar
• Hard black ash

Acrylic

• Synthetic
• Burns readily and melts
• Odour of burning meat or turmeric
• Black, irregular ash

Nylon

• Synthetic
• Burns briefly and melts
• Self extinguishing
• Smells like celery
• Hard grey bead that doesn’t crumble

Polyester, Modacrylic and other synthetics

• Acrid, sharp odours or smell of sweet chemicals
• Self extinguishing  
• Melt to a hard black bead

Polycotton

• Feels like cotton and have a similar creasing but melts rather than burns.
• Ash forms a hard bead that doesn’t crumble