Write the cloth spec

A fabric price is a yarn price plus a conversion cost, and the conversion cost is decided by the words below. This is also the section where most quality complaints start, because a cloth can meet its construction exactly and still be wrong.

Woven construction

Written as warp count by weft count over ends per inch by picks per inch, for example 40s x 40s / 133 x 72. The first pair is the yarn, the second is how densely it is packed. Together with the weave they decide the weight, the cost and the hand, and the arithmetic for turning them into a weight is on our learning page.

Weave

Plain is one over one: the firmest and the flattest. Twill is the diagonal, three over one in most shirting and denim: softer, drapes better, hides soil. Satin floats the yarn over several threads for lustre and snags more easily. A weave change alters both the cost and the behaviour of the garment.

Cover factor

How much of the surface the yarn actually covers. A low cover factor cloth is open, light and cheap, and it is also what a mill reaches for when asked to hit a price without changing the stated counts. Two cloths at the same construction can differ here.

Crimp

Yarn does not run straight through a cloth; it waves over and under. The extra length is crimp, and it is why a metre of fabric consumes more than a metre of yarn. Mills carry their own crimp allowances by loom and by construction, so a calculated consumption is a planning figure and not a specification.

Greige and finished weight

The same cloth weighs different amounts before and after finishing, and shrinks in width. A GSM agreed without saying which one is meant is an argument waiting to happen.

Knit gauge and stitch length

Gauge is needles per inch and sets how fine the loop structure is. Stitch length, or loop length, is how much yarn goes into each loop, and it is the single thing that decides a knit fabric’s weight. This is why a knit weight cannot be calculated from the yarn count the way a woven weight can: the machine setting decides it.

Knit structures

Single jersey is the plain knit, light and it curls at the edge. Interlock is denser, stable and does not curl. Rib stretches across. Pique has the textured surface used for polo shirts. Each has its own weight range and its own price for the same yarn.

Mercerising

Cotton treated with caustic soda under tension. It gains lustre, strength and dye uptake, so shades come out deeper and brighter on less dye. It is a real cost and a real difference, and it is visible.

Sanforising and shrinkage control

Compressive shrinking so the cloth does most of its shrinking before you cut it rather than after the customer washes it. Residual shrinkage is the number to specify, and it is tested by washing, not by opinion.

Dye class

Reactive dyes on cotton, disperse on polyester, vat where high fastness is needed. A polyester cotton blend needs two dyeings, which is why it is not simply the average of the two prices. The dye class decides the fastness you can promise.

Shade band and lot variation

Dyeing is a batch process, so shade drifts between lots and even across the width of one roll. A shade band is the agreed range. Cutting one garment from two lots is how a sleeve ends up a different colour from a body.

Fabric inspection

Rolls are graded by penalty points for faults, usually on the four point system, with a limit per hundred square yards. Without an agreed limit, "first quality" means nothing in particular.

Testing

Dimensional stability after washing, colour fastness to washing, rubbing, light and perspiration, pilling, tearing and tensile strength, and weight against tolerance. These are the tests that decide whether a complaint is yours or the mill’s.

What to put on the order for a roll of fabric

Every line below is one you can be given a straight answer on. A supplier who will not put one of them in writing is telling you something, and it is usually the most useful thing you will learn in the negotiation.

• Full construction: warp and weft count, ends and picks per inch, weave, and the finished width.
• Weight, stated as greige or finished, with the tolerance in per cent.
• The finish route in order, and whether it is mercerised, and to what.
• Maximum residual shrinkage in warp and weft, and the wash test it is measured by.
• Colour fastness grades required, test by test, and against which standard.
• Pilling grade, and the number of rubs it is tested to.
• Shade band, lot size, and whether cutting across lots is permitted.
• The fabric inspection system and the points limit you will accept.
• A sealed handloom or bulk sample, approved in writing, before bulk dyeing starts.

Shrinkage, fastness and pilling are normally tested to ISO or AATCC methods, and the method belongs in the contract because results differ between them. Fabric grading is usually the four point system. The above is standard trade practice compiled for orientation, not a specification.

These are standard trade definitions and typical published ranges, compiled by VeriMills for orientation. They are not a specification, they do not replace a test report, and where a figure here differs from your contract, your contract is the one that binds.