9 min readConcept sheetOften a 5-mark answer; definitions and small calculations in Section A

Yarn count and numbering systems: denier and tex

Yarn count shows fineness. In direct systems (tex, denier) a bigger number means a coarser yarn; in indirect systems (cotton count) a bigger number means a finer yarn.

TexGrams per 1,000 m of yarn

DenierGrams per 9,000 m of yarn

English cotton count (Ne)Number of 840-yard hanks in one pound

ConversionsDenier = 9 × tex; tex ≈ 590.5 ÷ Ne

Direct and indirect systems

Direct systemFixed length, weight measured. Count = weight of a standard length, so a higher number = heavier, coarser yarn. Tex (g per 1,000 m), decitex (g per 10,000 m), denier (g per 9,000 m). Used for filaments and man-made yarns; tex is the universal (ISO) system.

Indirect systemFixed weight, length measured. Count = number of length units in a unit weight, so a higher number = finer yarn. English cotton count (Ne): 840-yard hanks per pound; metric count (Nm): km per kg; worsted count: 560-yard hanks per pound.

Systems at a glance

System	Type	Definition	Mainly for
Tex	Direct	Grams per 1,000 metres	All yarns (universal system)
Decitex (dtex)	Direct	Grams per 10,000 metres	Man-made filaments
Denier	Direct	Grams per 9,000 metres	Silk and man-made filaments, hosiery
English cotton count (Ne)	Indirect	Number of 840-yard hanks per pound	Cotton and spun yarns in India
Metric count (Nm)	Indirect	Kilometres per kilogram (metres per gram)	Spun yarns, Europe
Worsted count	Indirect	Number of 560-yard hanks per pound	Worsted wool

Worked examples: denier and tex

Problem

(a) 450 m of nylon filament weighs 1.5 g. Find its denier and tex. (b) 120 m of cotton yarn weighs 1.8 g. Find its tex and its approximate cotton count.

Working

(a) Denier = weight (g) × 9,000 ÷ length (m) = 1.5 × 9,000 ÷ 450 = 13,500 ÷ 450 = 30 denier.
(a) Tex = 1.5 × 1,000 ÷ 450 = 1,500 ÷ 450 = 3.33 tex (two decimal places). Check: 30 ÷ 9 = 3.33.
(b) Tex = 1.8 × 1,000 ÷ 120 = 1,800 ÷ 120 = 15 tex.
(b) Ne ≈ 590.5 ÷ tex = 590.5 ÷ 15 = 39.4, which rounds to a 39s count (close to the common 40s).
(b) In denier, this yarn is 9 × 15 = 135 denier.

Answer

(a) 30 denier, 3.33 tex. (b) 15 tex, about 39s Ne (close to 40s), 135 denier.

Worked example: English cotton count

Problem

25,200 yards of cotton yarn weigh exactly one pound. What is its English cotton count?

Working

One hank = 840 yards.
Number of hanks = 25,200 ÷ 840 = 30.
Count = hanks per pound = 30. Check: 30 × 840 = 25,200 yards.

Answer

30s Ne. A 40s yarn would be finer and a 20s yarn coarser.

Yarn count and thread count

Yarn countFineness of one yarn (tex, denier, Ne). '2/40s' means two 40s singles plied together; the ply behaves like a 20s yarn.

Thread (fabric) countNumber of warp and weft yarns per inch (or cm) in a woven fabric, e.g. 100 × 80. Covered in Unit III.

Exam trap: a bedsheet's thread count describes how closely it is woven, not how fine its yarn is.

In daily life

Labels use these numbers: 15-denier stockings are sheer, 40-denier ones thicker; 2/40s mercerised cotton is a good sewing thread for uniforms. Very fine high-count cotton is cool for summer but wears out quickly in hard hospital laundering, where coarser, stronger yarns last longer.

Exam angle

2 marks: “Define denier and tex.” Denier is the weight in grams of 9,000 m of yarn; tex is the weight in grams of 1,000 m. In both, a higher number means a coarser yarn.

5 marks: “Explain the direct and indirect systems of yarn numbering with examples.” Direct: fixed length, weight measured; tex, decitex, denier; higher = coarser. Indirect: fixed weight, length measured; Ne, Nm, worsted; higher = finer. One small calculation.

10 marks: “What is yarn count? Explain the yarn numbering systems with suitable calculations.” Define count; direct and indirect systems with a table; worked examples for denier, tex and Ne; conversions; yarn count vs thread count.

Remember it

Direct = Denier = Dense: bigger number, thicker yarn. Indirect = cotton count: bigger number, finer yarn. Tex is 1,000 m, denier is 9,000 m, so denier = 9 × tex.