Overview
ISO 20616-2:2020 - "Graphic technology - File format for quality control and metadata - Part 2: Print Quality eXchange (PQX)" specifies an extensible XML 1.0 file format for exchanging print quality data and metadata between quality-control applications. PQX is designed for one-way transmission of raw measurement and production data (not pass/fail tolerances) so receivers can apply their own acceptance criteria. The standard is normative for an XML schema (Annex A) and includes informative materials on concepts and sample PQX files.
Key topics and requirements
- XML-based, extensible format: Conforms to W3C XML 1.0 and defines extendable constructs such as TagCollection and CustomResources for vendor-specific additions.
- Colour integration: Uses the same colour-data containers as CxF (ISO 17972 family), including compatibility with spectral and non‑spectral colour data (references to CxF/CxF3_Core.xsd).
- Raw data focus: PQX files intentionally exclude tolerance/evaluative information - they carry measurement and metadata only.
- Defined element model: The schema organizes press and quality data into elements such as PQXInfo, PrinterInfo, PressRunInfo, RunLength, InkCollection/Ink, ReporterCollection/Reporter, PrinterQA, AutomatedPressControl, CustomerItemCollection, SampleCollection, ColorReport, MeasurementSet, RegistrationReport, VarianceReport, ChannelReport, DefectReport/DefectSet, BarcodeReport, and CxF-related sample/reference elements.
- Normative and informative content: Includes an XML schema (normative), explanatory principles and concepts (informative), and sample PQX files to assist implementation.
Applications and who uses it
PQX is aimed at the graphic arts supply chain for reliable digital exchange of print quality and production metadata:
- Print service providers and printers (press runs, production metadata)
- Print buyers and brand owners (quality tracking and acceptance workflows)
- Quality control and color measurement vendors (spectrophotometer and inspection systems)
- MIS, workflow, and print-production software developers (data import/export, reporting)
- Color scientists and process-control engineers (data analysis without imposed tolerances)
Practical uses include sharing colour measurement sets, defect and barcode inspection data, registration and variance reports, and automated press-control logs between systems and stakeholders.
Related standards
- ISO 17972 series (CxF/CxF3 colour data exchange)
- W3C XML 1.0 (Extensible Markup Language)
- ISO/TC 130 (Graphic technology) guidance and other parts of ISO 20616
Keywords: ISO 20616-2, PQX, Print Quality eXchange, print quality data, XML schema, graphic technology, color measurement, quality control.
