Testing Fabrics for Fiber Content
Today, with modern technologies and the blending of many different fibers, a microscope and chemicals would be needed to really test for fiber content. However, the burn test is easy enough to do at home and fairly reliable.
Burn tests cannot identify blends. Therefore, this chart is limited to single fiber burn test. To test for acetate the acetone test would be more appropriate. Burn tests are dramatic in the sense that fire is involved and the test destroys the fiber you are testing.
Performing the test. Cut a small piece of fabric or ravel a few yarns from a place that will not affect the original piece. Hold the cut piece or yarns with tweezers, tongs, pliers, (anything but your fingers) over a sink. Ignite samples with a match or lighter.
Fibers and Their Reactions to Flame
Cellulosic Fibers (Cotton, Linen, Rayon)
Burns rapidly, with a yellow flame and continues to glow after it is removed from the flame. Smells like burning paper or leaves. Produces a soft, gray ash.
Protein Fibers (Silk and Wool)
Burns slowly, sizzling and curling away from the flame. Sometimes self-extinguishing when removed from the flame. Smells like burning hair or feathers. Produces a crushable black ash.
Burns and melts while in the flame and after removal from the flame. May smell like vinegar when burning. Produces a hard, brittle black bead.
Burns and melts while in the flame and after removal from the flame. Produces a hard, brittle black bead.
Shrinks away from the flame; then burns slowly and melts. Usually, self-extinguishing when removed from the flame. Smells like celery and leaves when burning. Produces a hard gray bead.
Shrinks away from the flame; then burns slowly and melts giving off black smoke. Usually self-extinguishing when removed from the flame. Smells slightly sweet when burning. Produces a hard black bead.
Test for acetate by putting a small cutting of fabric or a few yarns in a dish of acetone (nail polish remover). Acetate will disintegrate leaving, at most, dye behind or other fibers if it is a blended fiber fabric.