The easiest way to tell if fabric is 100% cotton or not is burning test. It provides valuable data regarding appropriate care and will help place a fiber into a specific category.
Cut small pieces of fabric you want to test and ignite it. Pay attention to the odor of the smoke and examine the ashes after they’ve cooled.
|Fiber||Burn or melt||Shrinks from flame||Odor||Residue||Other properties|
|Cotton||Burns only||No||Burning paper, leaves or wood||Fine, feathery, gray ash||/|
|Flax, hemp, jute, ramie, etc.||All burning characteristics same as cotton|
|Rayon||All burning characteristics same as cotton|
|Wool, mohair, cashmere, alpaca，etc.||Burns only||Yes||Very strong odor of burning hair||Black, hollow irregular bead which crushes easily to a gritty, black power||Self – extinguishing|
|Silk||Same as wool, except odor is not so strong and may smell like charred or burning meat ( no sulphur content like wool)|