High Quality Content by WIKIPEDIA articles! Denier is a unit of measure for the linear mass density of fibers. It is defined as the mass in grams per 9,000 meters. In the International System of Units the tex is used instead (see below). As with all metric system units, the denier has it's standard based in nature. A single strand of silk is one denier. Therefore, a sampled 9,000 meters length of silk will weigh one gram. The term denier is a literal combination of the words linear and density.The term micro-denier is used to describe filaments that weigh less than one gram per 9,000 meter length.