No single home test is 100% certain, but combining a burn test, a feel test and a water test gives a reliable read on whether a fabric is pure cotton, a cotton blend, or a synthetic. Pure cotton burns like paper, feels soft and slightly cool, and absorbs water quickly.
Three Simple Tests You Can Do at Home
- Burn test: snip a small thread and burn it (carefully, away from anything flammable). Pure cotton burns quickly with a steady flame, smells like burning paper, and leaves a soft grey ash. Polyester melts, curls away from the flame, smells chemical, and leaves a hard bead.
- Feel test: cotton feels soft, slightly matte and cool to the touch, and creases easily when scrunched. Synthetics tend to feel smoother, slippery or slightly warm, and spring back without holding a crease.
- Water test: a drop of water on pure cotton spreads and soaks in within a few seconds. On most synthetics, the drop beads up and sits on the surface instead of absorbing.
A word of caution: many everyday fabrics are cotton blends (cotton-polyester, cotton-viscose), not 100% cotton — these tests will show mixed results rather than a clean pass or fail. If you need a guaranteed fibre composition for a bulk or institutional order, a textile testing lab report is the only fully reliable method.
Terminology
- Fibre composition — the mix of raw fibres in a fabric (e.g. “60% cotton, 40% polyester”), usually stated on a garment label or a lab test report.
- Blend — a fabric woven or knitted from more than one type of fibre, combining properties of each (e.g. cotton’s breathability with polyester’s wrinkle resistance).
Need a lab-verified answer rather than a home test? Learn about our independent textile testing service or browse our product categories for verified cotton fabric.