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Stage 30 of 42 · Finishing & QC

Laboratory Testing

Physical, chemical and colour testing.

The lesson for this stage
Chapter 17 · Material Testing & Textile Laboratory

What really happens at this stage

Laboratory testing verifies that fabric, trims, and finished garments meet the physical and chemical performance the buyer specified, independent of how the garment looks or fits. Physical testing covers properties such as tensile and tear strength, seam slippage, colourfastness to washing and rubbing, pilling resistance, and dimensional stability after washing. Chemical testing screens for restricted substances and confirms fibre content, pH, and finish performance where relevant to the buyer's programme. Colour testing checks that shade, shade continuity across a bulk lot, and fastness to light, perspiration, and rubbing stay within the buyer's approved tolerance, since colour is one of the most visible and most disputed quality attributes in apparel.

Results are only meaningful if the sample tested truly represents the lot, so sampling protocol, conditioning of specimens, and following the buyer's specified test method precisely are as important as the equipment itself. A lab report showing a pass on an unrepresentative swatch gives false confidence and can let a genuine bulk fabric fault through to cutting. Internal labs handle routine screening and early-warning checks during development and bulk production, while accredited third-party labs are typically used for the buyer's formal pre-production and pre-shipment test reports. Retaining physical reference samples and past reports allows a factory to compare a new lot against history when a result looks borderline.

How it is done

  1. 1
    Confirm the test matrix

    Agree with the buyer which physical, chemical, and colour tests apply to this style, fabric, and market, referencing the buyer's specified test method for each.

  2. 2
    Draw representative samples

    Cut swatches from multiple positions across the fabric width and along different rolls in the lot, avoiding fabric edges or visibly flawed areas.

  3. 3
    Condition specimens

    Hold samples at standard temperature and humidity for the specified conditioning period before testing, since moisture content skews strength and dimensional results.

  4. 4
    Run internal screening

    Test shrinkage, colourfastness, and basic strength in-house during bulk production to catch a shifting fabric batch before cutting.

  5. 5
    Commission third-party testing

    Send pre-production and pre-shipment samples to an accredited external lab for the buyer's formal test report package.

  6. 6
    Review and act on results

    Compare each result against the buyer's approved tolerance, and where a value is borderline, retest a second sample set before releasing fabric to cutting.

Key metrics (indicative targets)

MetricWorking targetWhy it matters
First-pass lab test rateAbove 85 percent of tests passing on first submission (indicative)Frequent retests point to unstable fabric sourcing or process control problems upstream.
Colour shade approval cycle timeWithin 2 to 3 working days per submission (indicative)Slow shade approval delays bulk dyeing and can push back the entire cutting schedule.
Restricted substance screening coverage100 percent of applicable fabrics and trims screened per season (indicative)Compliance failures on restricted substances can block shipment or trigger a recall.
Dimensional stability after washWithin the buyer's approved shrinkage tolerance (indicative)Excess shrinkage after the consumer's first wash is a leading cause of customer returns.
Sample-to-lot correlation rateAbove 95 percent agreement between lab sample and bulk lot performance (indicative)Poor correlation means the sampling method is not representative of what actually ships.

Targets are indicative working ranges, not standard or legal limits.

Control points to check and sign off

  • Test matrix and applicable buyer test methods documented per style before bulk fabric booking.
  • Sample conditioning time and environment logged alongside each test result.
  • Retest triggers defined in writing for borderline or failed results.
  • Third-party lab accreditation and scope checked before sending formal pre-shipment samples.
  • All test reports archived and cross-referenced to the fabric lot and purchase order.

Common pitfalls and their consequences

  • Testing a single 'best' swatch instead of samples drawn across the roll, producing a pass that does not reflect the true lot.
  • Skipping conditioning time under schedule pressure, which distorts strength and shrinkage readings.
  • Relying only on internal lab results for buyer-mandated compliance tests that require third-party accreditation.
  • Approving a shade under the wrong light source, causing a metamerism complaint once garments reach the store under different lighting.
  • Not retesting after a supplier changes a dye lot or finish, assuming prior approval still applies to the new batch.

Main activities

  • Washing, finishing and pressing
  • Inline, endline and AQL final audits
  • Laboratory testing and shipment release

Quality risks

  • Test failures

Sustainability risks

  • Restricted chemistry

AI opportunities

  • Lab data analytics

Official sources

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