The truck backs up to the workshop gate with forty rolls of heavy washed twill, and none of them gets near the cutting table that day. Before a single metre is cut, each dye lot goes through three tests: a shrinkage wash, a colour rub test, and a weight check on the scale. Those three numbers decide whether the roll gets cut or goes back on the truck.

If you buy apparel in bulk, you already know how this plays out when it is skipped. The bulk goods come back a shade darker than the sample. The legs come out shorter than the approved measurements. A restock fits differently from the batch before it, and nobody can point at a document that explains why. Almost all of it starts at the fabric stage, weeks before anyone sews a seam. Here is what the three tests actually look like on our floor in Shishi, what numbers come out of them, and what you should be asking for before you approve bulk.

Three tests sit between the fabric truck and the cutting table.

The routine is simple enough to describe in one pass. A roll arrives, the dye lot gets a code, and the swatch room cuts samples from it the same morning. One set goes into a wash, one goes under a rubbing hand, and one goes on the scale. Results get logged against the lot code, and the cutting table only releases a lot once all three readings sit inside the range the counter sample established. Nothing in the chain is exotic. The value is that every decision downstream traces back to a number somebody wrote down.

The shrinkage wash happens before the pattern, not after it.

Cotton twill shrinks. That part is not a defect, it is physics: yarns relax when water and heat hit them for the first time. The question a buyer should care about is not whether the cloth shrinks but who moved first. We cut a marked swatch, measure it, wash and dry it the same way the finished garment will be washed, then measure it again. A reading of two to three percent in each direction is normal on washed cotton workwear, and two to three percent on a 100 cm front panel is a two to three centimetre change the pattern team has to know about.

So the pattern is graded against the tested shrinkage, not against a guess. When the style is garment washed later in production, the second shrinkage has already been accounted for. Skip the pre-test and the correction happens by accident: somebody presses a sample against a ruler after the fact and wonders why the bulk runs short. This is also the node where a restock quietly drifts, because a new dye lot can shrink differently from the one your first batch used, and the pattern has not changed.

Colour fastness is a rub test, not a promise.

Dry rub, then wet rub. A piece of white cotton cloth gets rubbed against the fabric under standard pressure, and the staining on the white cloth is read against a grey scale that runs from grade 1 to grade 5. Grade 4 or better on both dry and wet is the level most workwear buyers accept as a baseline, and that reading comes off a physical test card, not off a supplier sentence. Dark indigo and heavy black dyes are the ones we watch closest, because they carry the most loose dye into the test.

Different fabrics fail in different ways, which is why the test list does not change but the risk does. A printed lyocell linen shirt has its own questions around print fastness, a waxed or heavily washed cargo pant has questions around crocking on the darker panels. The point is not to memorise the scale. The point is that a rub grade is a number you can demand on paper, and a verbal assurance is not.

Weight goes on the scale three times per roll.

Weight gets measured with a circular die that cuts a fixed area, three positions per roll: middle and both selvedge ends. The three readings get averaged and compared against the counter sample, with a tolerance of roughly five percent either side on workwear twill. Cloth that lands light across every position did not get unlucky, it got woven light, and five percent on a 300 gsm spec is 15 grams you paid for and did not receive. We covered the full arithmetic on that gap, including the width trap between grams per square metre and grams per linear metre, in our piece on specing fabric weight for a wholesale order.

What happens when a roll fails one of the three.

A failed roll is rejected, photographed, logged against the lot, and sent back. Nobody cuts into it and hopes. That discipline sounds strict until you price the alternative: a defect caught in fabric costs cents per garment to walk away from, and the same defect caught in a finished carton costs the style, the delivery window and the relationship. The wash test alone takes about a day, and the other two take an afternoon. Against the weeks a rejected bulk consumes, three tests on receiving day are the least expensive hours in the whole production plan.

What reaches you with the shipment.

For each dye lot, the paperwork carries the three readings: the shrinkage figures the pattern was graded against, the dry and wet rub grades, and the weight readings with their tolerance. This part is worth repeating because the market is moving toward it. More buyers now ask for fastness, pilling and shrinkage reports before they ask about new designs at all, and a factory that cannot produce those readings per lot simply cannot answer the question.

Five questions to ask before you approve bulk

You do not need a lab of your own to hold this line. You need five questions, asked before the deposit, in writing:

• Which stage was the fabric tested at: greige, finished, or after the garment wash?
• What shrinkage reading did the pattern team compensate for, in both directions?
• What rub grade did the counter sample reach, dry and wet?
• Was weight read on which stage of cloth, and with what tolerance against the counter sample?
• Will the readings for my dye lots travel with the shipment?

A factory that answers all five without hesitating has already run the tests. One that goes quiet on question two is telling you the pattern team is guessing. Either way you have your answer before your money moves. This pairs well with the sampling side of the same discipline, which we laid out in our piece on how many sample rounds are worth running before bulk.

FAQ

Do these three tests hold up production?

The shrinkage wash takes about a day because the swatch has to dry fully before the second measuring. The rub test and the weight readings are same-afternoon work. On a normal order that is one to two days between fabric arrival and cutting approval, against the weeks a rejected bulk or a restocked fit dispute consumes later.

Can I check any of this on fabric I have already received?

Yes, at screening level. A marked swatch, a household wash, and a ruler will give you a usable shrinkage estimate. A piece of white cotton cloth and a firm hand will tell you whether dye transfers under dry and wet rubbing. A kitchen scale and a 10 cm template give a rough weight figure. Treat all three as filters, and treat the numbers in your contract as the ones the agreed test method produced.

Three tests on receiving day, three numbers per dye lot, and the arguments that used to surface in January get settled in October instead. That is the whole system, and we run it on every order that passes through our workshop in Shishi, large or small. Send us your spec and our team will answer within 24 hours.

Contact us for wholesale pricing