Wool fibers, which are primarily composed of keratin, exhibit numerous overlapping scales or plates that are all aligned in a single direction. When exposed to pressure, heat, and moisture, the scales of adjacent fibers interlock, forming the material known as felt. In a single inch of this material, there may be thousands of overlapping scales, which provides substantial strength to wool products while maintaining significant flexibility. Wool is also lightweight, highly absorbent, and readily dyed, making it a popular textile for apparel, rugs, and blankets.