ISO 17972-4:2018

Overview

ISO 17972-4:2018 - "Graphic technology - Colour data exchange format (CxF/X) - Part 4: Spot colour characterisation data (CxF/X-4)" defines a standardized exchange format for spectral measurement data of spot inks. It specifies how to describe the colour and opacity of spot colour inks (ink + substrate combinations) using the CxF framework so that spot inks can be reliably printed and proofed. The standard applies only to isotropic (paper‑like) substrates and to workflows where the same ink and paper combination characterised is used in production. ISO 17972-4 uses a CustomResource element within the CxF/CxF3 model to define minimum and recommended data for exchange, and supplies XML schema and example files for implementation.

Key Topics

• Spot colour characterisation: communicates spectral data and opacity for individual spot inks rather than process ink combinations.
• Conformance levels: three levels to match common workflows:
  • CxF/X-4 (Full Characterisation) - colour and opacity specified (includes measurements over substrate and black background).
  • CxF/X-4a (Single Background) - characterisation for inks printed on a single background.
  • CxF/X-4b (Single Patch) - characterisation for solid (100%) ink patches only.
• Measurement chart requirements:
  • Patches at 0% and 100% must be printed on the unmarked substrate.
  • For CxF/X-4 and CxF/X-4a, include at least one intermediate tint (e.g., 50%) and a minimum of 11 patches total.
  • For full characterisation, a second set of patches with the same tint levels must be printed on a black region.
  • Tint levels are recorded as percentages (0–100).
• Data structure and validation: leverages CxF3 Core plus a CxF/X-4 CustomResource. Annexes provide XML schema (CxF3_Core.xsd, ISO17972-4_schema.xsd) and examples; Annex C explains core validation.
• Scope limitations: metallic, pearlescent, or fluorescent inks may require extra fields beyond this part; ink production/process detail is outside scope but can be added via extensions.

Applications

ISO 17972-4 is used by:

• Brand owners and print buyers to ensure accurate reproduction of spot colours.
• Ink manufacturers to publish spectral and opacity data for spot inks.
• Printers and proofing houses to produce reliable proofs and predict printed appearance.
• Prepress and color management specialists, RIP and proofing software vendors, and instrument manufacturers implementing measurement exchange. Use cases include spot-ink proofing, cross-vendor colour communication, and automated RIP workflows that require spectral characterisation.

Related Standards

• ISO 17972-1 (CxF3 Core / relationship to CxF3)
• ISO 17972-2 and ISO 17972-3 (other CxF/X CustomResource usages)
• ISO 13655 (measurement practice guidance referenced)

Keywords: ISO 17972-4:2018, CxF/X-4, spot colour characterisation, colour data exchange, spectral measurement, spot inks, CustomResource, CxF3, proofing, printing.