The choice of fabric for sachets depends on various factors such as durability, breathability, and aesthetic appeal. It is crucial to select a fabric that allows air circulation while still retaining the scent of the filling. Natural fabrics like cotton or linen are commonly used due to their breathable nature and ability to hold fragrances effectively. They allow the scent molecules from the filling to permeate through their fibers without trapping them entirely. Additionally, these fabrics are durable and come in various textures and designs that can add visual appeal to the sachet itself. However, ultimately the best fabric for sachets comes down to personal preference and intended use - whether it's for decorative purposes or primarily meant for providing a gentle fragrance throughout your space.