How to read a grey fabric quality spec

A grey fabric spec from Surat is usually written as a short line of numbers. Once you know what each number means, you can compare qualities from different weavers and order the same cloth again.

The parts of a spec

Denier – how thick the yarn is

Denier is the weight in grams of 9,000 metres of yarn. A 60 denier yarn weighs 60 grams per 9,000 metres. Higher denier = thicker yarn. Polyester filament yarn is also described by its number of filaments, written after a slash: 75/36 means 75 denier made of 36 filaments.

Count – the cotton way of saying the same thing

Cotton and spun yarns use count (Ne): the number of 840-yard hanks that weigh one pound. Higher count = finer yarn – the opposite direction to denier. To convert roughly:

count (Ne) ≈ 5315 ÷ denier

So 75 denier ≈ 71s count, and 150 denier ≈ 35s count.

EPI and PPI – how tightly it is woven

• EPI (ends per inch): how many warp threads in one inch of width.
• PPI (picks per inch): how many weft threads in one inch of length. In Surat this is usually just called pick.

Reed

The reed is the comb on the loom that the warp ends pass through. The reed number tells you how many dents (gaps) there are per inch, and with the number of ends per dent it sets the EPI. Weavers often quote reed and pick instead of EPI and PPI. Because reed systems are not always written the same way, ask the weaver for the EPI as well if you are comparing qualities.

TPM – how much twist

TPM is turns per metre of twist in the yarn. Twist is added on a TFO machine. More twist gives a crisper, grainier, more crepe-like cloth; untwisted filament gives a smoother, shinier cloth. Some specs use TPI (turns per inch): TPI × 39.37 = TPM. The twist direction (S or Z) also matters for georgette-style fabrics.

Width

The grey width in inches, as the cloth comes off the loom. Finished width after processing is usually less, because the cloth shrinks. Ask your processor how much to allow.

Weight per taka and metres per taka

Grey cloth is sold folded in taka. A spec usually gives the metres per taka and the weight per taka in kg. Taka length is not standard across the market, so always check both numbers.

GSM

GSM is grams per square metre. It lets you compare cloth of different widths. Grey GSM is usually different from finished GSM.

Worked example

This is an example only, to show the arithmetic. It is not one of our qualities.

Parameter	Value
Warp	50 denier polyester FDY
Weft	75 denier polyester FDY, twisted
EPI × PPI	150 × 90
Width	44 inch
Metres per taka	100 m

1. Warp weight per square metre. One metre of width has 150 × 39.37 ≈ 5,906 warp ends. Each end is 1 metre long and weighs 50 ÷ 9,000 grams.

5,906 × 50 ÷ 9,000 ≈ 32.8 g

2. Weft weight per square metre. One metre of length has 90 × 39.37 ≈ 3,543 picks, each about 1 metre wide.

3,543 × 75 ÷ 9,000 ≈ 29.5 g

3. Grey GSM. 32.8 + 29.5 ≈ 62 GSM, before crimp. Yarn bends over and under in the weave (crimp), so the real figure is a few percent higher – roughly 64–66 GSM here. Size on the warp adds a little more.

4. Weight per taka. 44 inches is 1.118 m wide. One running metre weighs about 62.3 × 1.118 ≈ 69.6 g, so 100 m weighs about 7.0 kg, plus crimp.

If a supplier’s weight per taka is very different from what the spec suggests, ask why. It may be a different denier, more picks, or a different taka length.

A checklist for comparing qualities

1. Same yarn type and denier in warp and weft?
2. Same TPM and twist direction?
3. Same EPI and PPI (or reed and pick, on the same reed system)?
4. Same grey width?
5. Weight per taka and metres per taka – does the GSM work out the same?

See also the grey fabric glossary, or look at a real spec on our Renial grey fabric page.