AQL Sampling for Knitwear: How to Read an Inspection Report

By YZR Sweaters · 2026-09

An inspection report is only useful if you can tell whether the result was fair. That means knowing where the sample size came from, which AQL levels applied, and what the accept and reject numbers were.

What does AQL actually mean?

AQL stands for Acceptable Quality Limit — the defect level a buyer and a supplier agree to treat as acceptable for a given order. It is a quality target, not a promise of perfection.

Because checking every piece is slow and costly, the inspector examines a random sample and decides the fate of the whole lot from what it shows. The industry's sampling tables turn three inputs — lot size, inspection level and AQL value — into a sample size and a pass-or-fail threshold.

• Lot size — how many units the inspection covers.
• Sample size — how many units are pulled and checked.
• Accept number (Ac) — the highest defect count that still passes.
• Reject number (Re) — the count at which the lot fails.

How do you read an AQL sampling plan, step by step?

• Step 1 — Confirm the lot size. Count the units actually presented, not the units on the purchase order; a short shipment is a smaller lot.
• Step 2 — Choose the inspection level. General levels run from I (smallest sample) to III (largest), with level II the usual default.
• Step 3 — Read off the sample size. The table turns lot size and inspection level into a code letter, which sets the sample size.
• Step 4 — Apply the agreed AQL values. Majors and minors are set separately: 2.5 for majors and 4.0 for minors are common starting points, but confirm the levels with your inspection company rather than assuming. Critical defects are usually handled at zero tolerance.
• Step 5 — Count and compare. Every defect in the sample is recorded and classified. At or below Ac the lot passes; at Re it fails.

How do critical, major and minor defects differ?

• Critical — a defect that could make the garment unsafe or illegal to sell. The usual convention is zero tolerance: one finding fails the lot.
• Major — a defect that clearly affects how the sweater performs or looks on the shelf, such as a broken seam or a measurement outside tolerance.
• Minor — a defect that does not affect function and would not stop a sale, such as a loose thread end or a light mark.

Classification is where disputes start, because the same flaw can look minor to a factory and major to a buyer. Write the categories into the order with examples. Our overview of knitwear defects and inspection stages covers the flaw types themselves.

What is the difference between single and double sampling?

In single sampling, one sample is drawn and one decision is made. In double sampling, a smaller first sample is checked: clearly good passes, clearly bad fails, and only a count in between triggers a second sample. Double sampling can save time on clean lots but complicates the procedure, so the choice belongs in the inspection plan.

How do you read an apparel inspection report?

Check these in order.

• Lot size and sample size — do they match the agreed plan?
• AQL values and inspection level — the agreed levels, or defaults the inspector chose?
• Defect counts by category — critical, major and minor findings against Ac and Re?
• Critical findings — one critical defect normally decides the result on its own.
• Photographic evidence — defects, cartons and measurement points documented.
• Conclusion — pass, fail or pending. Pending means a document or test was missing, and it is not a pass.

What happens when a lot passes but customers still return goods?

That is the built-in limit of sampling. A pass means the defect level in the sample fell within the agreed limit; it does not mean the remaining cartons are clean. That is why the AQL level is a commercial decision about how much risk you carry, and why a post-sale complaints route still matters. If returns concentrate on one flaw, fix it as a specification problem on the next order.

When is 100% inspection the better choice?

Full inspection costs more per unit but removes the sampling gamble. Consider it for high-value cashmere or wool blends, children's knitwear, a first order with a new supplier, or a style where one visible flaw would be damaging. A buyer can request either full inspection or third-party sampling.

How should a buyer set AQL levels?

• Keep critical defects at zero tolerance on every order.
• Start stricter with a new supplier, then relax once the process is stable.
• Set tighter limits for visible areas — neckline, placket, front panel — than for hidden seams.
• Confirm the exact levels with your inspection company, then write them into the order; our knitwear supplier vetting checklist covers the points to settle first.

Note too that an inspection only covers what is visible on the day. Fibre content, colourfastness and shrinkage are settled by sweater lab testing, not by a visual check.

YZR Sweaters is a Dongguan knitwear manufacturer and supplier working on OEM/ODM programmes for brands, wholesalers and online retailers. We support full inspection as well as third-party sampling by SGS or BV, and can provide in-house inspection records before shipment. Our partner factories hold BSCI, SEDEX and Oeko-Tex certification and welcome factory audits.

Frequently asked questions