Overview
EN ISO 105-J03:2009 - Textiles: Tests for colour fastness - Part J03 defines a standardized method to calculate the colour difference between two specimens of the same textile material measured under the same conditions. The method produces a single-number metric, ΔEcmc(l:c) (often shown as ΔE (l:c)), that quantifies the extent to which a specimen does not match a reference. The procedure uses CIELAB tristimulus-derived values with the CMC (Colour Measurement Committee) modification to create an ellipsoidal acceptability space whose size is independent of the actual colour.
Key topics and technical requirements
- Colour space and inputs: Uses the CIE 1976 Lab* (CIELAB) values calculated from X, Y, Z tristimulus data; preferred illuminant/observer is D65/10° (table of other illuminant/observer combinations also provided).
- Components calculated: ΔL*, Δa*, Δb*, ΔC*, ΔE* (CIELAB), ΔH*. These feed into the CMC calculation to give ΔEcmc(l:c) and component CMC differences (ΔL, ΔC, ΔH).
- CMC equation and ellipsoid: The CMC formula weights lightness, chroma and hue by semi‑axes (lS, cS, S_H) determined from the reference L*, C* and hue (h). The standard fixes c = 1.0 and normally uses l = 2.0 (CMC(2:1)) to match typical textile visual assessment; other l values may be used for non‑textile surfaces.
- Tolerance and acceptability: The numerical ΔEcmc value permits specification of an acceptability tolerance (pass/fail limit) that is independent of the reference colour and the type of colour difference.
- Reporting requirements: Test reports must include the standard reference, sample identification, instrument/geometry details (spectrophotometer or colorimeter and CIE geometry), ΔEcmc values, l and c values, illuminant/observer, any acceptability tolerance, component differences if required, and test date.
- Supporting material: Annexes provide guidance on interpretation, representative data for software validation, and a sample computer program for calculating colour difference.
Applications and users
- Who uses it: textile manufacturers, dye houses, quality control laboratories, colourists, brand owners, specification writers, and instrument/software developers.
- Practical uses:
- Acceptance testing of dyed/printed textiles against standards or master samples.
- Supplier quality control and incoming inspection of colour batches.
- Colour tolerance specification for production and procurement.
- Validation and implementation of spectrophotometer or colour‑measurement software.
Related standards
- ISO 105 series (other parts of the ISO 105 family covering textile colour fastness tests).
- CIE recommendations for colourimetry (referenced for tristimulus and observer/illuminant data).
- See Annex A of ISO 105-J03 for interpretation guidance and ISO 105-A01 for the complete ISO 105 part listing.
Keywords: EN ISO 105-J03, ISO 105-J03:2009, colour difference, ΔEcmc(l:c), CMC(l:c), CIELAB, textiles, colour fastness, spectrophotometer, acceptability tolerance.