Burn Test · Mar 04, 2025

How to Identify Fabric Fiber Content: Burn Test & More!

by Irina McKenzie

At FABCYCLE Textile Waste Reuse Center, we receive thousands of different types of fabric. Most of the time, we don’t get any information about their fiber content because they come from a variety of sources. Since we specialize in deadstock and textile waste, we rarely have labels or supplier details to guide us.

So, how do we figure out what type of fabric we have?

One of the most effective, quick, and surprisingly fun ways to determine fiber content is the burn test. While it’s not 100% foolproof (especially for blended fabrics), it gives us a solid idea of what we’re working with.

If you’ve ever picked up a mystery fabric at a thrift store, a fabric swap, or even inherited some from a family member, you might have wondered: What is this fabric made of? Identifying fibers can help you understand how to sew, wash, and care for the material.

In this post, we’ll guide you through the burn test method, plus other sensory and visual clues that can help you make an educated guess about fabric content.

🔥 The Fabric Burn Test: How It Works

The burn test involves carefully burning a small swatch of fabric and observing how it reacts to the flame, how it smells, and the type of residue it leaves behind. Different fiber types burn in distinct ways, making this a useful identification method.

⚠️ Important Safety Precautions:

Always perform the burn test in a well-ventilated area, away from flammable materials.
Use tweezers or tongs to hold the fabric.
Keep a small bowl of water nearby to extinguish any lingering embers.
Never attempt this with large pieces of fabric—only test a tiny swatch!

How to Perform a Burn Test:

Cut a small strip (about 1 cm wide) of the fabric.
Hold it with tweezers over a flame (such as a candle or lighter).
Observe how it burns:
1. Does it catch fire quickly or slowly?
2. Does it self-extinguish?
3. Does it shrink away from the flame?
Smell the smoke—each fiber type has a unique scent when burned.
Examine the residue:
1. Does it crumble into ash?
2. Does it form a hard, melted bead?

🔍 Burn Test Results by Fabric Type

Each fabric type reacts differently to fire. Here’s a quick reference table to help identify your mystery fabric:

Fabric Type	Burn Reaction	Smell	Residue
Cotton	Burns quickly, bright yellow flame	Smells like burning paper	Soft, gray ash
Linen	Similar to cotton, but burns slightly slower	Burning grass or wood	Soft, gray ash
Silk	Curls away, burns slowly	Smells like burning hair	Brittle, black ash
Wool	Burns slowly, self-extinguishes	Burning hair or feathers	Black, crumbly ash
Rayon (Viscose, Modal, Lyocell)	Burns quickly, continues burning after flame is removed	Smells like burning leaves	Soft ash
Acetate	Melts, burns quickly, sometimes drips	Smells like vinegar or celery	Hard, black bead
Polyester	Melts, shrinks away, burns with black smoke	Chemical or sweet odor	Hard, round bead
Nylon	Melts, shrinks, may self-extinguish	Smells like celery or plastic	Hard, gray bead
Acrylic	Burns rapidly with a sputtering flame	Strong chemical odor	Hard, irregular bead

💡 Fun fact: Acetate fabric can smell like burnt celery when tested with a burn test!

👀 Additional Ways to Identify Fabrics Without Burning

While the burn test is helpful, sometimes you might not want to set your fabric on fire (totally understandable!). Here are a few other ways to identify fabric content:

1. The Touch Test

Cotton & Linen: Soft, breathable, often slightly rough to the touch.
Silk: Smooth, luxurious, slightly cool when touched.
Wool: Warm, fuzzy, sometimes scratchy.
Synthetic Fabrics: Slippery, smooth, sometimes stiff or plasticky.

2. The Wrinkle Test

Natural fibers like cotton, linen, and rayon wrinkle easily.
Synthetics like polyester and nylon resist wrinkles and stay smooth.

3. Water Absorption Test

Cotton and rayon absorb water quickly.
Polyester and nylon repel water and dry fast.

4. Look at the Weave & Selvage

Some high-end fabrics have their content woven into the selvage edge.
Knitted fabrics (like jersey) stretch more than woven fabrics.

🏷️ Why Identifying Fabric Content Matters

Knowing fabric content will help you as a sewist and maker to:

✅ Choose the right needle and stitch type.

✅ Understand if a fabric will shrink or stretch.

✅ Know how to properly wash and care for the fabric.

✅ Select the best material for their project.

At FABCYCLE, we use our expertise in fiber identification to process thousands of pounds of deadstock and textile waste. By performing burn tests and combining them with other sensory tests, we make educated guesses to help our community find the perfect fabric for their creations.

🔥 Final Thoughts

The burn test is a great starting point for identifying fabric content, but it works best when combined with other techniques like the touch, wrinkle, and water absorption tests.

Next time you come across a mystery fabric, try these methods! And if you're looking for high-quality, deadstock fabrics for your next project, check out our curated collection at FABCYCLE—where sustainability meets creativity. ♻️✨

Have questions about fabric identification? Drop them in the comments below or visit us at the Textile Waste Reuse Center! Happy sewing! 🧵

What’s Next? Part 2: How Fabric Identification Works in the Industry

While the burn test is great for home use, professionals use specialized tools like infrared spectroscopy, chemical testing, and microscopic fiber analysis to determine fabric content with precision.

In Part 2, we’ll explore how textile manufacturers, fashion brands, and sustainability experts test fabrics, why it matters, and how it impacts the way we source and use materials.Plus, we’ll break down what’s practical for home sewists versus what’s exclusive to textile labs!

Stay tuned!