Unit of fineness. The thickness or fineness of silk filament yarn is expressed in terms of denier, of silk, rayon or synthetic yarn. This is estimated by the number of half decigrams (0.05 g) which a hank of yarn weighs. Or, numerically, this is the weight in grams of 9000 metres of silk, rayon or synthetic yarn. The lower the denier, the finer the silk. If a hank of 9000 metres of yarn weighs 30 gms the yarn is 30 denier. See Fineness.