This page is for anyone at a garment factory who must interpret a colour fastness or shrinkage result and decide what a failed rating means for the order it belongs to: a merchandiser, a production manager, or a quality controller. Lesson 3.1 named the main physical and chemical tests an order goes through. This lesson goes deeper into the two tests a factory meets most often on almost every order, colour fastness and shrinkage, because both are rated on a scale rather than a simple pass or fail, and a person reading the result has to know what the scale means before deciding anything. This is chiefly a decision skill for the information flow of an order: reading a rating correctly, then deciding what it changes about the order. Without it, a rating just below the buyer's standard can be read as "close enough," when in fact it is a fail that the buyer's tech pack does not allow.
You need: Lesson 3.1's two test families, physical and chemical. If you have not read that lesson, the key terms below give you enough to continue.
By the end of this lesson you can:
Not covered here: the full set of physical and chemical tests an order goes through (Lesson 3.1); reading a complete test lab report section by section (Lesson 3.3); what happens once a test has actually failed close to shipment (Lesson 3.4); and building a complete testing tracker for an order (Lesson 3.5).
| Term | Meaning |
|---|---|
| Colour fastness | A rating for how well a fabric's dye resists fading or bleeding, usually stated as a numeric grade in a report's colour fastness section. |
| Grey scale | A standard numeric scale, typically 1 to 5, used to rate colour fastness; a higher number means less visible change or transfer. |
| Shrinkage test | A test measuring how much a fabric shrinks after washing or wet processing. |
| Required result | The specific rating or percentage the buyer's tech pack states a test must meet or better. |
| Actual result | The rating or percentage an independent testing lab actually measures for that fabric or garment. |
| Wash cycle | One complete run of a garment through washing, used both in production (Order B's own two denim washes) and in a shrinkage test's method. |
A colour fastness test rates how well a fabric's dye resists fading or bleeding, and its result is stated as a grade on the grey scale, a standard numeric scale from 1 to 5 where a higher number means less visible change. A shrinkage test measures how much a fabric or garment changes size after washing, and its result is stated as a percentage of the original measurement. Neither number means anything on its own; each is only meaningful next to the buyer's own required result, the specific grade or percentage the tech pack states the fabric must meet or better. A grey-scale rating of 4 is a pass only if the buyer's required result is 4 or lower on the scale of acceptable minimums; a shrinkage of 4% is a pass only if the buyer's allowed shrinkage is 4% or more. The rule is comparison, not the number by itself: read the actual result, read the required result, and compare the two in the direction each scale runs.
| What can differ | The shapes you meet | Why it matters |
|---|---|---|
| Buyer's required grey-scale grade | One buyer's tech pack may require grade 4 minimum for washing fastness; another buyer, on a different product, may accept grade 3. | A grade that passes one buyer's standard can fail another's; the factory checks that order's own tech pack, not a general industry habit. |
| Buyer's required shrinkage percentage | An export order such as Order B's denim may allow up to a stated maximum shrinkage after its fixed two washes; a domestic order for a local brand may set a looser or tighter limit depending on the product. | A fabric within one buyer's shrinkage allowance can still fail another buyer's tighter limit on the very same fabric. |
| Knit fabric vs. woven fabric | A knit fabric, such as Order A's single jersey, commonly shrinks more than a woven fabric such as Order B's denim, because knit structures relax more in washing. | A shrinkage result that would be alarming on woven denim can be a normal, passing result on a knit, and the reverse. |
| Make to Order (MTO) vs. Make to Stock (MTS) | An MTO export order tests one confirmed fabric lot against its buyer's required result before that lot ships; an MTS domestic brand may set its own internal required result and test each production run against its own standard rather than an external buyer's. | An MTS brand still needs a stated required result to compare against; "it looked fine on the last batch" is not a required result. |
| Number of wash cycles a shrinkage test runs | Order B's denim's own fixed two washes give the shrinkage test its real number of wash cycles to run before measuring; other orders may specify a different number of cycles. | A shrinkage percentage measured after the wrong number of wash cycles does not answer the buyer's actual question about that order. |
Delta Garments is producing Order B, 3,000 pieces of five-pocket jeans in 12 oz denim, for Northline Apparel, the export buyer paying by letter of credit. Order B's own fixed detail includes two washes as part of its finishing. Northline Apparel's tech pack states a required result for colour fastness to washing (grade 4 minimum on the grey scale) and a required result for shrinkage after Order B's own two washes (a maximum shrinkage the fabric must not exceed). The independent testing lab returns two numbers: the actual colour fastness grade and the actual shrinkage percentage, each measured on a denim sample that went through the same two washes the finished garment will go through. Karim, the production manager, must read both actual results against Northline Apparel's two required results before deciding whether Order B's denim can proceed.
The worked numberThe colour fastness result passes because the actual grade meets the required minimum exactly. The shrinkage result fails because the actual percentage is higher than the required maximum, even though the difference, 1.2 percentage points, looks small. A rating scale does not forgive a result that sits just past its limit; 4.2% is a fail against a 3% maximum in exactly the same way 8% would be.
The methodA common mistake is treating a shrinkage result that sits only slightly above the buyer's required maximum as effectively a pass, because the difference looks small next to the fabric's whole size. A required maximum is a limit, not a target to get close to; 4.2% against a 3% maximum is a fail by the same rule that makes 8% a fail, because the tech pack states a maximum the actual result must not exceed, not a range within which "close" still counts. Rounding a failed number down in one's own head does not change what the independent testing lab actually measured, and it leaves a factory believing an order has passed a test that its own report says it has not.
Two of the tests a fabric or garment goes through give back a number instead of a simple yes or no. One test checks how well the fabric's colour holds up; its result is a grade, usually from 1 to 5, where a higher number is better. The other test checks how much the fabric shrinks after washing; its result is a percentage, where a lower number is better. Neither number tells you anything by itself. You always compare it against the number the buyer actually asked for. If the colour grade meets or beats what the buyer wants, that test passes. If the shrinkage percentage is at or below what the buyer allows, that test passes too. If a shrinkage result is even a little over the buyer's limit, it is still a fail, no matter how small the difference looks.
Delta Garments is producing Order B for Northline Apparel, and the independent testing lab has returned both a colour fastness grade and a shrinkage percentage for the denim sample.
The test lab report line Karim is checking against, exactly as written:
Can Order B's denim proceed to cutting on this result? Decide before you open the decision.
No. The actual shrinkage result, 4.2%, is above Northline Apparel's required maximum of 3%, so this test is a fail; the fabric cannot proceed to cutting on this result.
The two facts that decide this are the report's own two numbers, actual 4.2% against required maximum 3%, and Northline Apparel's own rule that the tech pack states a maximum the fabric must not exceed, not a target to approach. Delta Garments should hold the fabric, investigate the cause with the denim mill, and retest before committing any fabric to cutting, because cutting fabric that has already failed a required test risks the whole 3,000-piece order.
This lesson's cost is framed by what a wrong decision at this point risks, since the immediate cost of the test itself is fixed and small. If Delta Garments cuts Order B's 3,000 pieces from fabric that has already failed its shrinkage test, every finished pair of jeans risks shrinking out of Northline Apparel's accepted size range after the buyer's own customer washes them, a defect that is discovered only after shipment and after Delta Garments has already spent its full cutting, sewing, and washing cost on the order. Holding the fabric for retest, instead, costs only the retest's normal lab fee and a short delay before cutting starts, a cost Order B's denim timeline of 22 weeks can absorb if the retest happens promptly, unlike a full-order defect discovered after shipment.
This course's testing tracker records the buyer's required result and the independent lab's actual result in separate columns for every test line, so the two numbers are always compared side by side rather than judged separately. [Download the tracker](templates/T09-C03-testing-tracker.xlsx).
| Test name | Required result | Actual result | Result |
|---|---|---|---|
| Colour fastness to washing | Grade 4 minimum | Grade 4 | Pass |
| Shrinkage after 2 washes | 3% maximum | 4.2% | Fail |
1. A colour fastness result comes back as grade 3 on the grey scale, and the buyer's required result is grade 4 minimum. Is this a pass?
2. A shrinkage result comes back as 2.5%, and the buyer's required maximum is 3%. Is this a pass?
3. A different order's tech pack sets a shrinkage maximum of 5% instead of Order B denim's 3%, and its actual result is 4.2%, the same number Order B's denim failed on. Is this new order's result a pass or a fail?
| EN | AR | FR | TR | Meaning |
|---|---|---|---|---|
| Colour fastness | ثبات اللون | Solidité des couleurs | Renk haslığı | A rating for how well a fabric's dye resists fading or bleeding, usually stated as a numeric grade in a report's colour fastness section. |
| Grey scale | مقياس الرمادي | Échelle de gris | Gri skala | A standard numeric scale, typically 1 to 5, used to rate colour fastness; a higher number means less visible change or transfer. |
| Shrinkage test | اختبار الانكماش | Test de rétrécissement | Çekme testi | A test measuring how much a fabric shrinks after washing or wet processing. |
| Required result | النتيجة المطلوبة | Résultat requis | İstenen sonuç | The specific rating or percentage the buyer's tech pack states a test must meet or better. |
| Actual result | النتيجة الفعلية | Résultat réel | Gerçek sonuç | The rating or percentage an independent testing lab actually measures for that fabric or garment. |
| Wash cycle | دورة الغسيل | Cycle de lavage | Yıkama döngüsü | One complete run of a garment through washing, used both in production and in a shrinkage test's method. |
This lesson taught how a colour fastness or shrinkage result is rated and what a failed rating means. The next lesson teaches how to read a complete test lab report, with every section this course covers, and decide whether it passes the buyer's own standard. Back to the course map