ISO 105-A11:2012 PDF

Overview

ISO 105-A11:2012 - "Textiles - Tests for colour fastness - Part A11" specifies requirements for using digital imaging techniques to determine colour change and staining in textiles. The standard defines the required apparatus, camera and illumination settings, calibration/verification procedures, and software outputs for converting digital measurements (CIEDE2000) into conventional grey‑scale grades. Note: this part is not intended for assessment of colour fastness to light (ISO 105 B series).

Key topics and technical requirements

• Scope: Determination of change in colour and staining by digital imaging techniques (Annexes A and B).
• Digital camera: Effective resolution ≥ 3.0 MP; optical (not digital) zoom to capture the full assessment area; camera mounted at 0° to specimen and aligned parallel; PC connection and system software control of camera settings.
• Verification chart / calibration: Use a colour verification chart (Annex C) to verify camera output to CIE XYZ for every pixel. Verification required at system start-up, after camera setting changes, and at manufacturer‑specified intervals.
• Accuracy & repeatability: Performance expressed as CIEDE2000 colour differences:
  • Accuracy acceptable if maximum ΔE00 < 5.0 and median ΔE00 < 1.0.
  • Repeatability acceptable if maximum ΔE00 < 1.0 and median ΔE00 < 0.4 (ten consecutive measurements).
• Illumination cabinet: Opaque cabinet with diffuse lighting by a D65 simulator, light level 400–900 lx, spectral quality to CIE S 012/E and CRI > 95; evenness variation ≤ 4% across the assessment area.
• Specimen area & masks: Assessment area ≤ 300 × 210 mm; system grey internal surfaces and masks (approx. Munsell N5–N7) to avoid colour bias; white tile traceable to national standard for spectrophotometer checks.
• Software outputs: System software must compute ΔE00 (and ΔL00), convert numerical results into a grey‑scale rating for change in colour or staining, and record verification history and performance.

Practical applications and users

ISO 105-A11:2012 is designed for:

• Textile test laboratories and quality control teams performing fastness testing.
• Apparel and textile manufacturers seeking objective, reproducible colour‑fastness grading.
• Third‑party test houses and certification bodies requiring traceable digital methods.
• Instrument and software vendors developing digital imaging systems for textile colour measurement. Benefits include improved repeatability, digital records, and automated grading options (operator‑selected area or automatic grading), supporting faster decisions in production and compliance testing.

Related standards

• ISO 105-A01 - General principles of testing for colour fastness.
• ISO 105 B series - Colour fastness to light (not compatible with A11’s grey‑scale approach).
• CIE S 012/E and CIE 13.3 - Referenced for daylight simulator spectral quality and colour rendering metrics.

Keywords: ISO 105-A11:2012, colour fastness, digital imaging, textiles testing, CIEDE2000, D65 simulator, camera calibration, verification chart, illumination cabinet.