The appearance of high-quality silk has a pearl-like color, has the performance of diffuse refraction to light, is clean, has few impurities, and the silk road is orderly and neat; while the poor quality silk is often added with chemicals such as bleach to make its appearance. It is pale, without luster and moisturizing, with more impurities and chaotic silk road.
High-quality silk feels smooth, smooth and elastic to the touch, without hard clumps; while inferior silk feels rough, non-flexible, and non-moisturizing. There are relatively more cocoon stems, cocoon blocks, cocoon pieces, and pupae.
Silk with oily or musty smell is inferior.
Silk has no flame retardancy when burned, and stops burning when it separates from the flame. After burning, it becomes loose ash, with the smell of burnt hair.
The better the silk strength, the better the quality. Studies have shown that the tensile strength of super mulberry silk should be stronger than that of iron wires of the same diameter. High-quality silk has excellent recovery elasticity; while inferior silk has poor fiber properties such as strong elongation and recovery elasticity