A garment that reaches a shop floor has passed through a dozen departments, and any one of them can sink it. A fabric flaw missed at goods-in becomes 400 defective shirts. A marker planned badly wastes 8% of the cloth on every order. A measurement error caught at final inspection instead of in-line means rework on the whole run.
The industry manages this with structure: defined stages, defined checkpoints, and a statistical standard for deciding what passes. This guide covers how garment production actually flows, where quality control sits within it, and how the AQL system works.
It’s the starting point for everything in our garment manufacturing and QC section.
The Production Flow
1. Sampling and Development
Before bulk production, the factory produces a series of samples, each answering a different question:
- Proto sample — does the design work as a physical garment?
- Fit sample — do the measurements and fit meet the spec?
- Size set — does the fit grade correctly across the size range?
- Pre-production (PP) sample — made from bulk fabric and trims, this is the approval gate. Production shouldn’t start until it’s signed off.
- Golden sample — the approved reference held on the floor, against which everything is judged. Every dispute later resolves back to this.
The tech pack underpins all of it: measurement spec with tolerances, construction details, stitch types, fabric and trim specifications, labelling and packing instructions. An incomplete tech pack is the root cause of a remarkable share of quality disputes, because it leaves the factory to guess and then blames them for guessing wrong.
2. Fabric Sourcing and Inspection
Fabric arrives and gets inspected before anything is cut. This is the cheapest possible point to catch a problem, and the industry standard method is the 4-point system.
Defects are scored by length:
| Defect length | Points |
|---|---|
| Under 3 inches | 1 |
| 3–6 inches | 2 |
| 6–9 inches | 3 |
| Over 9 inches | 4 |
Points are totalled and normalised per 100 square yards. A commonly used threshold is 40 points per 100 square yards — above that, the roll is typically rejected. No single defect scores more than 4 points, regardless of how long it is.
Fabric is also checked for GSM against spec, shade consistency across and within rolls, shrinkage, and colourfastness. Shade variation is a particular trap: fabric from different dye lots can look identical in the roll and obviously different once cut panels sit side by side in a finished garment.
3. Cutting
Cutting starts with the marker — the layout plan showing how pattern pieces fit onto the fabric width. Marker efficiency, usually 80–90%, directly determines fabric waste, and fabric is typically the single largest cost in a garment. A few percentage points of marker efficiency is real money at volume.
Fabric is then spread in layers (the lay), cut, and bundled by size and colour. Key controls at this stage: spreading without tension (fabric stretched during spreading relaxes afterward and the panels come out undersized), cutting accuracy against the pattern, and bundle labelling so panels from the same lay stay together — which is what prevents shade variation within a single garment.
4. Sewing
The sewing floor is where most labour cost sits. Work is organised into a line, with the garment broken into operations distributed across operators.
Line balancing is the central problem: every operation takes a different amount of time, and the line runs at the speed of its slowest station. A poorly balanced line has operators idle at some stations and work piling up at others.
Different operations need different machines — lockstitch for topstitching and general seaming, overlock for seam finishing and knit construction, flatlock and coverstitch for hems on knits, bartack machines for reinforcement, buttonhole and button-attach machines. The machine mix on a line is determined by the garment.
5. Finishing
After sewing: thread trimming, pressing, spot cleaning, folding, labelling, tagging, and packing. It’s routine work that disproportionately determines the customer’s first impression — a well-made garment that arrives creased and covered in loose threads reads as poor quality.
Some garments also go through wet processing at this stage — garment dyeing, washing, enzyme treatment, or the various distressing processes used on denim.
Quality Control
QC is not a single inspection at the end. It’s staged across production, and the whole point of that structure is that problems get cheaper to fix the earlier you find them.
Stage 1: Pre-Production
Checking materials and approving the PP sample before cutting begins. Fabric inspection, trim verification, shrinkage and colourfastness testing, and confirming the PP sample matches the tech pack.
A defect caught here costs a roll of fabric. The same defect caught at final inspection costs the whole order.
Stage 2: In-Line (DUPRO)
In-line inspection — sometimes called DUPRO, “during production” — typically happens when the order is around 30–40% complete. Inspectors check workmanship, measurements, and construction while production is still running.
This is the highest-value checkpoint in the whole system, and the one most often skipped. A systemic error found at 30% completion gets corrected for the remaining 70%. The same error found at final inspection means rework across the entire order, or rejection.
Some floors use a traffic light system, where each operator’s output is checked periodically and marked green, yellow, or red, giving supervisors a live view of where defects are originating rather than a post-hoc count.
Stage 3: Final Random Inspection
Conducted once the order is essentially complete — commonly 80–100% finished and packed. A statistical sample is drawn at random from across the production run, not from the top of the nearest carton.
What’s checked: measurements against spec with tolerances applied, visual defects (loose threads, uneven seams, staining, print registration), labelling and content accuracy, size distribution across cartons, and packaging condition.
This is where AQL is applied.
Understanding AQL
AQL stands for Acceptable Quality Limit. It’s the statistical sampling standard, based on ISO 2859-1, that decides whether a batch passes or fails.
The logic is practical: inspecting all 5,000 units of a 5,000-unit order is possible but rarely economical. AQL instead defines how large a random sample to inspect, and how many defects that sample may contain before the batch is rejected.
Defect Categories
Critical — safety or regulatory hazard. A broken needle left in a garment. Zero tolerance, always.
Major — a defect a customer would likely notice and object to, or that affects function or saleability. Broken seams, wrong measurements beyond tolerance, obvious staining.
Minor — a small deviation from spec unlikely to affect saleability. A slightly loose thread, minor irregularity.
AQL Levels
The conventional apparel setting is 0 / 2.5 / 4.0 — zero critical defects permitted, 2.5% for major, 4.0% for minor. Stricter levels (AQL 1.0) are used for luxury; looser ones for promotional goods.
Sample sizes come from the ISO 2859-1 tables, based on lot size and inspection level. General Inspection Level II is the usual default. For a lot of around 550 units, that typically means inspecting about 80 pieces.
If defects in the sample exceed the threshold, the batch fails. The usual consequence is 100% re-sorting to identify and rework defective units, followed by re-inspection.
What AQL Doesn’t Mean
A batch passing at AQL 2.5 is not a defect-free batch. It’s a batch whose defect rate falls within an agreed statistical tolerance. Some defective units will ship. That’s the deliberate trade the standard makes — near-certainty would cost more than it’s worth for most product.
Brands who don’t understand this sometimes treat any customer complaint as a QC failure. It isn’t; it’s the system working as designed. If a lower defect rate genuinely matters, the answer is a stricter AQL level or 100% inspection, both of which cost more.
Measurement Tolerances
Every measurement in a tech pack should carry a tolerance — commonly ±0.25 to ±0.5 inches depending on the dimension and garment type.
Tolerances exist because fabric is not rigid. Cloth relaxes, stretches, and shrinks; a knit panel measured five minutes after cutting differs from the same panel an hour later. Demanding zero tolerance isn’t rigour, it’s a misunderstanding of the material.
Tolerances that are too loose, though, produce garments that technically pass and visibly don’t match each other on a rail.
Common Defects
Fabric defects — holes, slubs, shade variation, barré (horizontal streaking in knits), skewing.
Cutting defects — notches missing or misplaced, panels cut off-grain, shade mixing within a garment.
Sewing defects — skipped stitches, broken stitches, seam puckering, uneven stitch density, open seams, wrong stitch type used, needle damage on knits.
Measurement defects — dimensions outside tolerance, inconsistent grading between sizes.
Finishing defects — oil stains from machines, pressing marks, loose threads, incorrect or missing labels, poor packing.
Print and embroidery defects — registration errors, cracked prints from undercuring, embroidery puckering from wrong stabiliser choice.
Many of these trace directly back to fundamentals covered elsewhere on the site — needle and stitch selection, stabiliser choice, curing temperature.
Compliance and Auditing
Beyond product quality, buyers increasingly audit factories on social and environmental compliance. Common frameworks include BSCI, SEDEX/SMETA, WRAP, and ISO 9001 for quality management systems.
Audits typically cover working hours and wages, health and safety, building and fire safety, child and forced labour, environmental management, and business ethics. For export-oriented manufacturers these are effectively a precondition of doing business with most Western brands.
Costing
A garment’s cost breaks down roughly into fabric (usually the largest share), trims and accessories, cutting and making (CM — the labour charge), finishing and packing, overhead, and margin.
Because fabric dominates, marker efficiency and cutting waste have outsized effects on profitability. A 2% improvement in marker efficiency across a large order often exceeds what’s achievable by squeezing labour cost.
CM or CMT (cut, make, trim) is the charge for converting supplied materials into finished garments. FOB pricing includes materials and delivery to port. Understanding which basis a quote uses is essential when comparing suppliers — the numbers aren’t comparable otherwise.
Where to Go From Here
- SOP / QC / Flow Charts — standard operating procedures, inspection checklists and process flow documentation
Related areas:
- Apparel & Clothing — the finished products and what construction quality looks like from the buyer’s side
- Fabric Types & Specs — GSM, construction and specification reading
- Fabric Dyeing — wet processing, shade matching and colourfastness
- Sewing & Embroidery — machine types, stitch classes and construction technique
Frequently Asked Questions
What does AQL 2.5 actually mean? It means up to 2.5% of the inspected sample may carry major defects before the batch is rejected. It does not mean 2.5% of the shipment will be defective, and it does not guarantee a defect-free shipment — it’s a statistical tolerance for deciding pass or fail, not a promise about every unit.
What’s the difference between in-line and final inspection? In-line (DUPRO) happens during production, usually around 30–40% completion, so problems can still be corrected on the remaining units. Final inspection happens when the order is essentially finished and determines whether it ships. In-line is where quality is actually built; final is where it’s verified.
What is the 4-point system? The standard method for grading fabric quality before cutting. Defects are scored 1 to 4 points by length, totalled, and normalised per 100 square yards. A common acceptance threshold is 40 points per 100 square yards. It catches fabric problems at the cheapest possible stage.
Who should perform the AQL inspection — the factory or the buyer? The factory runs its own internal QC, but the final AQL inspection that determines shipment should come from the buyer’s own team or an independent third party. A factory inspecting its own output and declaring it acceptable has an obvious conflict of interest — the point of the standard is that it’s neutral.
What is a golden sample? The approved reference garment held on the production floor, representing exactly what the bulk should look like. Every quality question during production resolves back to it. Without one, “correct” becomes a matter of opinion.
Why do measurements have tolerances at all? Because fabric isn’t rigid. It relaxes, stretches, and shrinks with handling, humidity, and time, so identical cutting produces slightly different finished dimensions. Tolerances (commonly ±0.25 to ±0.5 inches) acknowledge that reality. Demanding zero tolerance isn’t achievable in textiles.
Do small orders need AQL inspection? Yes, though the sample size scales down. Even for small runs, using a structured standard gives you objective data on a supplier’s performance and establishes a repeatable process before you scale. For very small orders, 100% inspection is often practical anyway.
What’s the difference between CM and FOB pricing? CM (cut, make) or CMT (cut, make, trim) is a labour-only charge — you supply the materials, the factory converts them. FOB includes materials plus delivery to port. Quotes on different bases can’t be compared directly, which is a common source of confusion when sourcing.
