One of the VERY FIRST blog posts I ever typed out for my Domestic Geek Girl blog, was a “Shoppers Guide to the LA Fabric District” (or something like that). Anyway, one of the main tips I gave was to check the fabric with the “Fabric Burn Test”.

Being a pyro and an amateur seamstress, I just assumed everyone knew what that was. But then I got a couple of requests asking me to clarify what that was, and how to do it. At the time, my husband was leaving for Navy boot camp, and I was not in the mood or frame of mind to invest time in catching random pieces of fabric on fire and then blog about it. (Yeah, it was THAT bad.)

But anyway, I’ve had this blog post in mind since the very start of this blog. And while it’s taken me awhile to get around to it, it’s better late than never, eh?! So! Here we go!

What’s the Point in Identifying Fabrics?

Well, sometimes fabric is not always what it claims to be. If you’ve ever bought fabrics on eBay or flea markets, you’ll know what I mean. My LA Fabric District shopping warning in regards to the fabric burn test is from experience.

My hubby and I bought 12 yards of a fabric from the downtown Los Angeles marketplace that claimed to be linen. Yet when we tried to dye it (a natural cellulose fabric that should have easily taken the dye we used on it), it WOULD NOT take. A quick burn test revealed, hey! This isn’t 100% linen. It was clearly a synthetic blend, which doesn’t dye as well with the dye we were using.

So whether you are interested in using all natural fabrics, need to know the fabric type for dying or shrinking purposes and precautions – or are just plain curious! – the burn test is an effective and reliable method for fabric identification.

The What and the How of Fabric Burn Testing

The test itself is simple. You catch fabric on fire. You stare at the fire. You smell it. You play with it. You poke around at the remains. And then you feel like an amazing Sherlock Holmes of textiles because you have rightly deduced what the unmarked fabric you just destroyed was.

So! Are you ready to play? Here what you do:

1. Cut a small piece of fabric that you’d like to test. A one inch strip is sufficient, though you may want something a tad larger so you don’t burn yourself.

2. Grab some tweezers, some long matches, and a small glass container, like a condiment dish or ashtray and head outside with your fabric in hand. Make sure that’s it’s not windy, because that’s no good. Whatever you do, make sure you are in a well ventilated area inside – especially if you are testing synthetics. (We did these photos indoors, next to the open sliding glass door, and it still wasn’t ventilated enough to ventilate the stink – and toxins! -of burning synthetics.)

3. Place your fabric strip into your container and ignite a corner of the fabric. Take note of these primary things:

Does it burn completely, or does it self-extinguish?

Does it burn into ash, or does it melt into char?

What does it smell like?

Is the smoke white, or dark?

After the burn, what color and texture is the ash, or char?

Unraveling the Fabric Burn Results

Natural Cellulose Fabrics (Cottons and Linens)

These will ignite and burns quickly. The flame should flare up and leave a glowing ember after flame is removed, or extinguished. Smoke from cellulose is white or very light colored and smells like burnt paper or leaves. The ash is light gray or white and is very soft, collapsing upon touching.

Natural Protein Fabrics (Silks and Wools)

These burn slowly and while they do not melt, then have a tendency (if you look VERY carefully) to shrink away from the flame before igniting. They generally have trouble catching fire, and will not stay lit after the flame is removed. Protein fabrics produce very little smoke, and the smoke smells like burnt hair or feathers. The ash is a gritty powder or a dark brittle, both easily crushable.

Synthetic Fabrics (Nylons, Polyesters and Acrylics)

These ignite and burn EXTREMELY quickly – exercise caution. The fiber curl away from the flame, melt, and can drip (be very cautious!) leaving a hard plastic-like bead or lump of char behind. Burning these fabrics will produce black smoke and hazardous fumes. Synthetics burn with strong, acrid, sickly sweet chemical or burnt meat smells.

The Oddball Synthetic-Natural Fabric (Rayon)

The trickiest fabric to determine is rayon. It feels like, looks like and burns just like cotton. While it is technically made from natural product, it is synthetically manufactured, making it the red headed step-sibling that neither natural nor synthetic fabrics want to claim as their own. Rayon is readily accepted by those concerned about eco-friendly cloth manufacturing, and is in many natural fabric wardrobes since it carries all the benefits that cotton does. (Click here to see Health Benefits of Wearing Natural Fabrics).

However, if determining cotton from rayon is important to you, the ONE way you can tell the two apart is that cotton has an afterglow once the flame is removed, while rayon does now. Remove the flame, and rayon should not have any glowing / residual burning. Other than that, it burns like cotton in literally every other way – smell, smoke, ash, etc.

Some General Tips and Guidelines for Fabric Burning

The potential results are many and varied (especially when you get into BLENDED fabrics!) but here are some general guidelines:

– If the fabric curls away from the flame and doesn’t readily ignite, it is a synthetic fabric. Natural fabrics will readily ignite as the flame draws near.

– Dark plumes of smoke generally denote a synthetic fabric. White smoke generally denotes a natural fabric.

– Smoke that smells like chemicals, burning plastic or burning meat mean that it is a synthetic. Natural fabrics burning smells like grass, paper or hair.

– If the remnants of the burned fabric have charred hard lumps, or beads, it is generally a synthetic fabric. If the remnants are ashes that are soft and fine and collapse upon touch, it is generally a natural fabric.

To get a better feel for how each type of fabric reacts, do experimental burn tests on fabrics you know are made from cotton, cotton/polyester blends, and full on synthetic fibers. And above all, be careful and have fun!

Have you used the fabric burn test before? If not, think you’ll give it a shot?