Denier

DEN is the abbreviation for denier and stands for the fineness of yarn in textiles. A denier is equal to the weight in grams of 9km of yarn.
Calculation: 1 denier = 1g/9km.

The lower the number, the finer the yarn. Because of this, 1000-gauge fabric is made from heavier yarns and has a coarser structure than 500-gauge fabric. 500 or 1000 gauges are often used for backpacks and holdalls, and around 15 denier for women`s tights.