Fabric composition can be identified through visual inspection and touch. Natural fibers such as cotton are soft and skin-friendly, with a slightly rough feel and a certain degree of fluffiness; linen is relatively stiff and highly breathable; silk is smooth, soft, and has a natural luster; wool is fluffy, elastic, and has good warmth retention. Chemical fibers such as polyester and nylon have a smooth, crisp feel or some elasticity, but relatively poor breathability. By observing the fabric's luster, feel, and elasticity, its fiber composition can be preliminarily determined. Composition can also be identified through physical or chemical testing methods. For example, the burning method is commonly used: take a small amount of fiber, ignite it, and observe the burning speed, smoke, odor, and ash form. Cotton and linen burn quickly, leaving powdery ash with a burnt smell; silk and wool burn slowly, leaving hard ash with a smell similar to burnt hair; polyester, nylon, and other chemical fibers produce molten droplets when burning and have a pungent odor. Microscopic observation of the fiber surface structure or dissolving specific fibers in solvents can also be used for identification.
For industrial and laboratory identification, instrumental analysis methods can also be employed. Methods such as Fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), or X-ray diffraction can accurately identify the chemical composition of fibers. Modern testing methods can quickly and accurately distinguish between natural fibers, chemical fibers, and blended fabrics, providing a reliable basis for textile production, quality inspection, and market supervision.