Of the four knitted fabric failures below, spiralling side seams from torque is the one that reaches the end user before it reaches the inspection report.
Knitted fabric: why failures cluster around one or two parameters
In knitted fabric, the parameters in the table below are not independent. Weight and Stitch length between them explain most field failures, and both are routinely omitted from quotations because they are expensive to guarantee and easy to leave vague.
| Parameter | Typical range | Why it decides failure | Weight | 120-320 gsm | Apparel hand and opacity. Tolerance of +/- 5 % is normal, +/- 10 % is a claim waiting to happen. | Stitch length | 2.6-3.4 mm | Looser stitch is softer and pills faster; tighter is firmer and heavier. | Courses and wales | 18-32 cpi / 14-24 wpi | Density check that catches a lightweight fabric sold as heavy. | Width | open 160-180 cm / tubular 60-90 cm | Tubular costs less per kg and more per cut panel. |
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1. Skew / torque
What you see. Side seams spiral after washing, garments twist on the body.
Why it happens. High twist yarn, poor relaxation, or tubular fabric slit without rest.
How to catch it before you order. AATCC 179 skew after home laundering, measure before and after.
What to specify instead. Specify <= 5 % skew, require relaxation before cutting, and buy open width for critical styles.
2. Shrinkage beyond claim
Why it happens. Insufficient compaction, or a compactor setting changed between lots.
How to catch it before you order. ISO 6330 domestic wash at 40 C, then ISO 5077 dimensional change, 3 cycles.
What to specify instead. Specify 3-cycle figures, not 1-cycle, and hold the compactor setting as a controlled parameter.
3. Barre (fabric bars)
What you see. Horizontal bands appear after dyeing, worst on dark shades.
Why it happens. Yarn count variation or uneven tension across the beam.
How to catch it before you order. Visual inspection on a light box after dyeing; count bands per 10 m.
What to specify instead. Yarn lot control and tension monitoring; reject at greige if bands are visible before dyeing.
4. Pilling
What you see. Surface balls up under abrasion, especially at cuffs and under bag straps.
Why it happens. Short staple, loose stitch, or a brushed finish without anti-pill treatment.
How to catch it before you order. ISO 12945-2, 2000 and 7000 rubs.
What to specify instead. Longer staple cotton, tighter stitch, or an enzymatic anti-pill finish.
Knitted fabric: building a test plan you will actually run
| Test | Method | Acceptance | Dimensional change | ISO 6330 + ISO 5077 | <= 5 % after 3 washes | Skew | AATCC 179 | <= 5 % | Pilling | ISO 12945-2 | >= grade 3-4 at 2000 rubs | Colour fastness to washing; measured on structure, jersey, interlock, rib or fleece | ISO 105-C06 | >= grade 4 change, >= 3-4 staining | Bursting strength | ISO 13938-1 | report value |
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Knitted fabric: what the report should contain
- Structure jersey, interlock, rib or fleece — measured at three positions on the roll, recorded as a number rather than pass or fail On knitted fabric that is structure at jersey, interlock, rib or fleece.
- Weight 120-320 gsm — cut from the middle of the lot, not from the end of the roll For knitted fabric it is weight at 120-320 gsm that settles it.
- Stitch length 2.6-3.4 mm — read at 23 C / 50 % RH after conditioning, not straight off the machine On knitted fabric, skipping this is what produces spiralling side seams from torque.
- Shrinkage 5 % length, 4 % width — checked on production material, at in-process rather than only at pre-shipment For knitted fabric, the figure to write down is stitch length at 2.6-3.4 mm.
- Skew 5 % or less — stated in the purchase order with the test method beside it On knitted fabric that is structure at jersey, interlock, rib or fleece.
- ISO 6330 for domestic washing, ISO 13938-1 for bursting strength — run to the method named above; the report travels with the lot For knitted fabric it is weight at 120-320 gsm that settles it.
Specification ranges for knitted fabric are on the product page.
Questions buyers ask before ordering
What drives the price of failure modes and tests at tolerance of 120-320 gsm?
On failure modes and tests, 120-320 gsm applies to the roll as delivered.
Is 120-320 gsm achievable at our volume on failure modes and tests?
On failure modes and tests, we hold 120-320 gsm.
How do you verify tolerance against 120-320 gsm on failure modes and tests?
On failure modes and tests, 120-320 gsm is what we hold on repeat lots.
The test plan for knitted fabric
The minimum set on knitted fabric
| Test | Method | Acceptance | Dimensional change | ISO 6330 + ISO 5077 | <= 5 % after 3 washes | Skew | AATCC 179 | <= 5 % | Pilling | ISO 12945-2 | >= grade 3-4 at 2000 rubs | Colour fastness to washing; held at structure, jersey, interlock, rib or fleece | ISO 105-C06 | >= grade 4 change, >= 3-4 staining | Bursting strength | ISO 13938-1 | report value | GSM | ISO 3801 | +/- 5 % of nominal |
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Sampling for knitted fabric, and where it goes wrong
For a first order of knitted fabric, take three positions along the run and one sample per colour, then test dimensional change on all of them rather than on a composite.
Condition the samples before testing. Several knitted fabric results move by 10-20 % between a dry laboratory and a humid one, which is why two labs can disagree on the same material without either being wrong.
Reading a knitted fabric report properly
- Structure jersey, interlock, rib or fleece — measured at three positions on the roll, recorded as a number rather than pass or fail On knitted fabric, skipping this is what produces spiralling side seams from torque.
- Weight 120-320 gsm — cut from the middle of the lot, not from the end of the roll For knitted fabric, the figure to write down is stitch length at 2.6-3.4 mm.
- Stitch length 2.6-3.4 mm — read at 23 C / 50 % RH after conditioning, not straight off the machine On knitted fabric that is structure at jersey, interlock, rib or fleece.
- Shrinkage 5 % length, 4 % width — checked on production material, at in-process rather than only at pre-shipment For knitted fabric it is weight at 120-320 gsm that settles it.
- Skew 5 % or less — stated in the purchase order with the test method beside it On knitted fabric, skipping this is what produces spiralling side seams from torque.
- ISO 6330 for domestic washing, ISO 13938-1 for bursting strength — run to the method named above; the report travels with the lot For knitted fabric, the figure to write down is stitch length at 2.6-3.4 mm.
The three tests buyers skip and regret on knitted fabric
For knitted fabric that usually means skew measured after the wash or exposure the product will actually see, because skew / torque does not appear in a conditioned laboratory.
Shrinkage beyond claim is usually a construction failure rather than a material one.
Third, retention. It is the only way to know whether weight changed or the conditions did.
Turning test results into a purchase order clause on knitted fabric
Full parameter ranges are on the knitted fabric page; the checks that hold those ranges in production are described on the quality control page.
How often to re-test on knitted fabric
| Stage | What to test | Frequency | Development sample | All parameters in the specification; read against structure, jersey, interlock, rib or fleece | Once per development | First production lot | All parameters, plus the end-use test; written as structure jersey, interlock, rib or fleece | Every lot for the first three; measured on structure, jersey, interlock, rib or fleece | Repeat lots | Critical parameters and the one that failed before; held at structure, jersey, interlock, rib or fleece | Every lot | Annual | Full panel, including ageing where relevant; read against structure, jersey, interlock, rib or fleece | Once a year, or after any process change; written as structure jersey, interlock, rib or fleece |
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Retained samples: the cheapest insurance in the order on knitted fabric
For knitted fabric, the sample should include the finish, not just the base material, because skew / torque usually starts in the finish or the additive rather than the substrate.
The test plan for knitted fabric, by order size
| Order | Tests to run | What it establishes | Sample or trial | Dimensional change | Whether the material can meet the requirement at all; measured on structure, jersey, interlock, rib or fleece | First production order | Dimensional change, Skew, Pilling | The baseline every later lot is compared against; held at structure, jersey, interlock, rib or fleece | Repeat orders | Dimensional change plus the parameter that failed last time | Whether the process has drifted; read against structure, jersey, interlock, rib or fleece | Annual or after a process change; written as structure jersey, interlock, rib or fleece | Full panel | That nothing has moved in the background; measured on structure, jersey, interlock, rib or fleece |
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For knitted fabric, the one test never worth dropping is dimensional change, because it is the one that predicts skew / torque.
The claim file for knitted fabric, and how long to keep it
Claims on knitted fabric are lost on documentation far more often than on material. By the time spiralling side seams from torque appears, the sample is gone and the knitted fabric lot is cut, so the file is the case.
- The signed specification, with structure at jersey, interlock, rib or fleece and weight at 120-320 gsm on the same page as the knitted fabric price.
- The sealed bulk approval sample for knitted fabric, dated — not the development sample.
- The lot record showing structure as measured on knitted fabric, not as passed.
- Photographs of the knitted fabric consignment at goods-in, before the material was cut.
- The knitted fabric inspection report naming the method: ISO 6330 for domestic washing, ISO 13938-1 for bursting strength.
Keep the knitted fabric file for the warranty period plus one season — usually 24 months in export. A shelf costs nothing; a knitted fabric shipment without the file costs the whole order.
Two of the five are almost always missing on knitted fabric, and they are the two that decide it: the bulk approval sample and the measured structure value.
Building a knitted fabric specification?
Send what you have — structure, weight, target market. We reply with the band we would hold and the two parameters we would test before the first bulk run.
Products in this range
Related reading
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- Oxford Fabric Specification Guide: D Number, Coating and Waterproof Rating
Sample cut with your values on it · Neutral packing and private label · Consolidation, documents and lead times
