Quality problems on a shirt order rarely appear out of nowhere. They follow a pattern: a spec that was never written down, a mid-production change nobody flagged, and an inspection that happened after the goods were packed. AQL inspection exists to catch that pattern before it reaches your customer.
What AQL actually means
Acceptable Quality Level (AQL) is a statistical sampling standard. Rather than checking every piece, you inspect a defined sample and accept or reject the batch based on how many defects appear in that sample. It is a balance between cost of inspection and risk of escape.
For apparel, the common starting point is AQL 2.5 for major defects and AQL 4.0 for minor defects, with critical defects held at zero tolerance.
The three defect classes
- Critical — unsafe or unsellable (sharp needle fragments, wrong size on the label versus the garment, banned substances). Zero tolerance: any critical defect fails the batch.
- Major — affects function or clearly reduces saleability (broken stitching, mismatched collar, significant colour deviation).
- Minor — cosmetic issues a customer may accept (loose thread ends, slight measurement drift within tolerance).
Agreeing these classes in writing, before production, is the single most effective quality control step available to a buyer.
Where inspection should happen in the process
Three checkpoints cover most of the risk:
- Pre-production — verify the approved sample against the bulk fabric and trims. Catch specification drift here, when it is still cheap to fix.
- During production (DUPRO) — inspect partway through the run. This is where you catch a systematic fault that would otherwise repeat across thousands of pieces.
- Pre-shipment (PSI) — inspect finished, packed goods before they leave. This is the last point at which a problem can be fixed without a shipping delay.
Most buyers only run the third. Adding the second is where the largest savings usually hide.
Sample size and measurement
The inspection sample size scales with the order quantity rather than being a fixed number. For a mid-size order, expect inspection of roughly 80–125 pieces drawn at random. Alongside visual checks, a set of measurement points is taken and compared against the size chart tolerances.
A supplier who cannot produce a measurement report is not running a measurable quality system.
Clauses to put in every purchase order
- The agreed AQL levels and defect class definitions
- Who pays for a failed inspection and the re-inspection
- The rework timeline and whether shipping is held
- The approved sample as the contractual reference, retained by both sides
- Measurement tolerance table for every size
Common shirt defects to watch for
- Stitch density outside specification (too loose tears, too tight puckers)
- Collar and cuff interlining bubbling after wash
- Shade variation between panels from different fabric rolls
- Button hole sizing inconsistent with button diameter
- Size chart drift beyond tolerance across the run
The bottom line
Quality is a process, not an inspection. But when you cannot be on the floor every day, a written AQL agreement plus a mid-production check is the highest-leverage protection you can buy.
Ask us how our multi-stage inspection process works on your next shirt order — get in touch.