Identify rayon, silk, polyester silk: rayon is bright, slightly rough and hard, and has a clammy and cold feeling, let go after holding it tightly with your hand, there are more wrinkles, there are still marks after flattening, pull out the cloth and rub it wet with the tongue, rayon is straight and easy to pull and break, and the elasticity is different when dry and wet. Silk luster is soft, soft to the touch, delicate texture, rubbing each other can produce a special sound, commonly known as "silk sound" or "silk sound", let go after holding it tightly by hand, wrinkles are few and not obvious, and the dry and wet elasticity of silk products is consistent. Polyester filament has strong reflectivity, large stiffness, rapid rebound, crispness, good wrinkle resistance, strong and powerful, and is not easy to break.