The protein fiber of silk is composed mainly of fibroin and is produced by certain insect larvae to form cocoons. ... The shimmering appearance of silk is due to the triangular prism-like structure of the silk fibre, which allows silk cloth to refract incoming light at different angles, thus producing different colors.

Silk is a natural protein fiber that is obtained from the cocoons of silkworms. It is known for its lustrous appearance, which is a result of the unique structure of the silk fiber.

Factors that make silk lustrous:

1. Refraction of light: Silk fibers have a triangular prism-like structure that refracts light at different angles. This results in a shimmering effect that gives silk its characteristic luster.

2. Smooth surface: Silk fibers have a smooth surface that reflects light evenly, creating a glossy appearance.

3. High density: Silk fibers are densely packed, which allows them to reflect more light and appear more lustrous.

Fibre to Fabric:

Fibre to Fabric is the process of converting natural fibers into textiles or fabrics. The process involves several steps, including:

1. Harvesting: Natural fibers such as cotton, silk, wool, and jute are obtained from plants, animals, or insects.

2. Cleaning: The fibers are cleaned to remove impurities such as dirt, oil, and seeds.

3. Spinning: The fibers are spun into yarns using a spinning wheel or machine.

4. Weaving: The yarns are woven into fabrics using a loom.

5. Dyeing: The fabrics are dyed to add color and improve their appearance.

6. Finishing: The fabrics are finished to improve their texture, durability, and appearance.

In conclusion, silk's lustrous appearance is due to the unique structure of the fibers, which refract light at different angles, have a smooth surface, and are densely packed. The Fibre to Fabric process involves several steps, including harvesting, cleaning, spinning, weaving, dyeing, and finishing.