Common Knitwear Defects and How to Prevent Them in Production

Understanding common knitwear defects helps brands communicate effectively with manufacturing partners and set realistic quality expectations. This article identifies common defects and how to prevent them.

Category 1: Yarn-Related Defects

Slubs and Thick Places

Irregular thickness in yarn creates visible bumps in the fabric.

Causes: Inconsistent yarn spinning, poor quality raw material Prevention: Use OEKO-TEX certified yarn suppliers, test yarn before production

Color Variation (Barre)

Horizontal stripes of different shades across the fabric.

Causes: Mixing yarn from different dye lots, inconsistent tension Prevention: Use single dye lot per order, document dye lot numbers

Pilling

Small fiber balls forming on the fabric surface.

Causes: Short fiber yarns, loose twist, poor fiber quality Prevention: Specify pill-resistant yarns, test fabric before approval

Category 2: Knitting Defects

Dropped Stitches

Missing stitches that can unravel the garment.

Causes: Machine malfunction, incorrect tension, damaged needles Prevention: Regular machine maintenance, in-line inspection

Needle Lines

Vertical lines caused by individual needle variation.

Causes: Worn or damaged needles, inconsistent needle alignment Prevention: Replace needles regularly, check machine setup before production

Press-Off

Complete fabric separation during knitting.

Causes: Yarn breakage, power interruption, machine jam Prevention: Monitor production continuously, use machines with automatic stop sensors

Category 3: Finishing Defects

Spirality (Twisting)

Garment twists after washing, seams don’t align.

Causes: Yarn twist imbalance, improper relaxing Prevention: Use balanced twist yarns, allow adequate fabric relaxation

Shrinkage

Garment shrinks more than expected after washing.

Causes: Inadequate pre-shrinking, incorrect yarn specification Prevention: Pre-shrink fabric before cutting, specify wash care correctly

Color Bleeding

Dye transfers to other areas during washing.

Causes: Poor dye fixation, incorrect dye selection for fiber Prevention: Test colorfastness before production, use certified dyes

Category 4: Sewing and Linking Defects

Open Seams

Seams separate under tension.

Causes: Incorrect linking tension, insufficient seam allowance Prevention: Train linking operators, set tension standards

Puckered Seams

Seams appear wavy or gathered.

Causes: Mismatched fabric and thread tension, incorrect needle size Prevention: Match thread to fabric weight, test seam before production

Skip Stitches

Stitches are missing in the seam.

Causes: Incorrect machine timing, blunt needle Prevention: Maintain machines, replace needles frequently

Our Defect Prevention System

At JIERQI Clothing, we use a multi-layered approach:

1. Supplier qualification: Only work with vetted yarn suppliers
2. Pre-production checks: Test yarn, review machine setup
3. In-line inspection: Catch issues during production
4. Final inspection: 100% visual check + AQL measurement check
5. Defect tracking: Log and analyze defects for continuous improvement

Setting Realistic Quality Expectations

No manufacturing process achieves 100% perfection. The goal is to minimize defects and catch them before shipment. A 98%+ pass rate on first inspection is realistic for well-managed knitwear production.

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Concerned about quality for your collection? Contact our QC team to discuss our quality processes.