Denier is a unit of measurement that is used to determine the fiber thickness of individual threads or filaments used in the creation of textiles and fabrics. Fabrics with a high denier count tend to be thick, sturdy, and durable. Fabrics with a low denier count tend to be sheer, soft, and silky.
In terms of fills, in order to be considered a “microfiber” the fiber must be less than 1 denier, which is extremely fine. This gives the fill its airy weight, downy feel, and soft, silky texture. In comparison, a human hair is 20 denier, whereas Standard Fiber’s microfibers are typically 0.9 denier or less.