02 FIBER CLASSES · 05 COUNT SYSTEMS · ISO 2060 / 2061
Fibers and yarns, explained from the molecule up.
From cotton’s cellulose chains to polyester’s polymer draw — the structure, properties, and count math behind the threads every garment is made of.
What’s in this section
Natural fibers
Cotton, wool, silk, linen, jute, hemp — fiber structure, properties, and how to read a fiber content label.
Explore →
Synthetic fibers
Polyester, nylon, acrylic, spandex — polymerization, draw ratio, and why the same polymer behaves differently as filament vs staple.
Explore →
Yarn construction
Ring, rotor, air-jet, friction spinning — how twist direction (S vs Z) and plying change hand, strength, and pilling.
Explore →
Yarn count systems
Convert between Ne, Nm, Tex, Denier, and Decitex with ISO-compliant math — and learn which system to use when.
Explore →
Featured reading
Yarn count explained: Ne, Nm, Tex, Denier
The five major yarn count systems, when each is used, and how to convert between them without losing your place.
Open →
02
Yarn count calculator and converter
Free ISO 2060 / 2061-compliant converter between Ne, Nm, Tex, Denier, and Decitex. No login, instant result.
Open →
03
GSM to yarn count conversion
Working backward from finished-fabric GSM to the yarn count you need to knit or weave it.
Open →
Why engineers trust these guides
Every fiber and yarn guide is written or reviewed by a practicing textile engineer with a degree in textile engineering — and the count math is ISO-audited, not approximated.
Frequently asked questions
What’s the difference between a fiber and a filament?
A fiber is the smallest unit of a textile — short (staple) or long (filament). Cotton and wool are staple fibers; silk is a natural filament; polyester and nylon are extruded as continuous filaments before being cut into staple for spinning.
Which yarn count system should I use?
It depends on the market. Cotton uses Ne (English count). Wool and worsted use Nm (metric count). Synthetic filament and technical textile use Tex / Denier / Decitex — Tex is the ISO-preferred unit, Denier is still common in the US apparel trade.
Why do S-twist and Z-twist matter?
Twist direction affects how yarns behave in weaving and knitting — pairing two Z-twist singles into an S-twist ply (the most common configuration) balances torque and prevents the finished fabric from skewing or curling.
Are the count converters ISO-compliant?
Yes. Yarn count math follows ISO 2060 (Tex system) and ISO 2061 (methods of test). The converter page documents the standard it implements and links to the official source.
Open the converters
FOUR WORKING CALCULATORS · ISO-COMPLIANT · FREE, INSTANT, NO LOGIN