Overview
ISO 105-A08:2001 - Textiles - Tests for colour fastness - Part A08: Vocabulary used in colour measurement - is the ISO vocabulary reference for colour measurement terms used throughout the ISO 105 series. First published in 2001 and prepared by ISO/TC 38 (Textiles), SC 1 (Tests for coloured textiles and colorants), this part does not prescribe test methods but standardizes the definitions and terminology (e.g., CIELAB, ΔE, spectral reflectance) used within the context and scope of ISO 105. Its primary purpose is to ensure consistent language across textile colour fastness testing and reporting.
Key Topics
The standard defines core colour-measurement concepts and instruments, including:
- CIELAB (CIE 1976 L, a, b*) colour space** and derived metrics such as CIE L, a, b***, chroma (C*), hue (h*) and ΔE* (CIELAB colour difference).
- CIE tristimulus values and CIE chromaticity coordinates (x, y, z) for colour specification.
- Standard observers (CIE 1931 2°; CIE 1964 10°) and standard illuminants relevant to textiles (A, C, D65 and F-series).
- Instrumentation terminology: spectrophotometer, tristimulus colorimeter, and perfect reflecting diffuser (calibration basis).
- Spectral descriptors: spectral power distribution (SPD), spectral reflectance, spectral transmittance, and radiation bands (UV, visible, IR).
- Visual assessment terms: grey scale (for change and staining), whiteness, depth, tinctorial strength, and fluorescent whitening agents (FWA).
- Colour-difference evaluation notation (e.g., ΔE variants such as CMC) and related parameters (CMC ellipsoid semi-axes).
Applications
ISO 105-A08:2001 is essential for anyone involved in textile colour measurement and quality assurance:
- Textile testing laboratories and quality control teams use the vocabulary to produce consistent test reports across ISO 105 parts.
- Colour measurement and instrument manufacturers (spectrophotometers, colorimeters) reference these definitions for product specifications and calibration guidance.
- Dye and pigment formulators, product development teams, and brand quality specialists rely on consistent terms when specifying colour tolerances (ΔE), illuminant conditions, and observer angles.
- Standards writers, educators, and auditors use the standardized terminology to harmonize requirements and interpret test results.
Related Standards
- ISO 105-A01 - General principles of testing (ISO 105 series)
- ISO 105-A02 - Grey scale for assessing change in colour
- ISO 105-A03 - Grey scale for assessing staining
Standardized vocabulary from ISO 105-A08:2001 ensures accurate communication of colour measurement results across the textile industry, improving reproducibility, instrument interoperability, and quality control.