Production & quality
Knitwear quality control: from fabric inspection to AQL
Knitwear quality gets built in stage by stage and cannot be inspected in at the end. The essentials are 4-point fabric inspection, relaxing the fabric before cutting, panel and inline sewing checks, measurement against the size chart, an AQL-based final inspection, and 100% metal needle detection.
Key takeaways
- Fabric is graded with the 4-point system before cutting.
- AQL sampling follows ISO 2859-1 / ANSI/ASQ Z1.4, and General Inspection Level II is the usual default.
- A common apparel setting is AQL 2.5 for major and 4.0 for minor defects, with zero tolerance for critical defects. Agree yours with the supplier.
- 100% needle detection is standard for children's wear and school uniforms.
Quality is a process, not a final check
A final inspection can only find problems that are already there. The checks that matter most come earlier: before the fabric is cut, while panels are being sewn, and before garments are packed.
The stage-by-stage checklist
| Stage | What is checked |
|---|---|
| Pre-production | Shrinkage built into the pattern; graded pattern vs size chart |
| Fabric | 4-point inspection; shade roll to roll; 24–48 h relaxation |
| Cutting | Tension-free spreading; stripe matching; defective panels removed |
| Decoration | Position and colour vs approved sample |
| Sewing | Stretch seams; shoulder tape; inline checks |
| Pressing | No shine or crushed loops; even dimensions |
| Final | Measurements vs size chart; AQL inspection; 100% needle detection |
| Packing | Size stickers, carton ratio, warning-printed polybags |
The 4-point fabric inspection system
Each fabric defect is scored from 1 to 4 points depending on its size, and the total for a roll decides whether it passes. On knits, inspectors look especially for skew, holes, shade variation, oil stains and barré (horizontal bands).
AQL final inspection
AQL (acceptance quality limit) is a statistical sampling method. Instead of checking every garment, the inspector draws a sample based on the lot size and inspection level, and the lot passes or fails on how many defects turn up.
The standards behind it are ISO 2859-1 and ANSI/ASQ Z1.4, and General Inspection Level II is the usual default. Defects are classed as critical (safety), major (likely to cause a return) or minor. A common apparel setting is 0 critical, 2.5 major and 4.0 minor, but the levels are agreed order by order.
Typical defects in knitwear
- Major: holes, open seams, broken stitches, measurements outside tolerance, shade variation between panels, misplaced logos.
- Minor: untrimmed threads, slight marks, small stitching irregularities.
- Critical: anything that makes a garment unsafe, such as a broken needle fragment or a prohibited drawcord on children’s wear.
Needle detection
Every finished garment passes through a metal needle detector. This is standard for children’s wear and school uniforms, and many buyers in Europe and North America expect it.
Final thoughts
Ask any supplier where in the process they check quality, and don’t stop at whether they do a final inspection. A factory that inspects fabric, relaxes it, checks panels and seams inline and detects needles on every piece will pass AQL inspections, because the defects never reach the end of the line.