Overview
SIST ISO 13655:2018 - Graphic technology: Spectral measurement and colorimetric computation for graphic arts images specifies standardized procedures for making spectral measurements and computing colorimetric values for reflective, transmissive and self‑luminous graphic arts specimens (including flat‑panel displays). The standard defines measurement modes, data formats and computation rules so that colorimetric results are comparable across instruments and workflows used in print production and graphic imaging.
Key topics and technical requirements
- Measurement modes (M0, M1, M2, M3)
- M0: legacy/incandescent‑type illumination (compatibility with older instruments).
- M1: illumination matched to CIE D50 (recommended for graphic arts).
- M2: UV‑cut condition (no substantial radiation below 400 nm).
- M3: same as M2 plus cross‑polarization for specular control.
- Spectral measurement requirements for reflectance, transmittance and spectral radiance (self‑luminous displays): wavelength range, sampling interval, bandpass and measurement geometry.
- Recommended data resolution - the standard recommends 5 nm interval and 5 nm bandpass for tristimulus integration; 10 nm instruments are allowed if bandpass correction (e.g., ASTM E2729) is applied. Use of wider sampling/bandpass is deprecated except for legacy monitoring.
- Fluorescence and optical brightening agents (OBAs) - procedures to address fluorescence effects and their interaction with instrument illumination and viewing conditions.
- Colorimetric computations and color difference metrics - conversion of spectral data to tristimulus values, CIELAB (Lab)* calculations and standardized ΔE formulas including CIEDE2000.
- Instrument standardization, reporting and metadata - requirements for instrument adjustment, required and recommended reporting fields, and electronic data formats.
- Normative and informative annexes covering sample backing, UV‑cut conformance tests, bandpass widening procedures, inter‑instrument agreement methods, certified reference materials and worked examples.
Practical applications
- Ensures consistent color measurements in prepress, pressroom QC, color management, proofing and device characterization.
- Supports accurate colorimetric assessment for offset, flexography, gravure, screen and digital printing, packaging inspection and display calibration.
- Helps manufacturers of spectrophotometers and spectroradiometers implement interoperable measurement modes and reporting formats.
Who should use this standard
- Color technologists, print production managers, QA labs, ICC/profile engineers, instrument manufacturers and software developers working in graphic arts and imaging who require reproducible spectral and colorimetric data.
Related standards and references
- ISO 3664 (viewing conditions for graphic arts and photography)
- ASTM E2729 (bandpass correction guidance referenced by SIST ISO 13655:2018)
Keywords: SIST ISO 13655:2018, spectral measurement, colorimetric computation, graphic arts, CIELAB, CIEDE2000, spectrophotometer, M1 measurement, UV‑cut, optical brightening agents.
