PTPGE API

Periodic Table of Print & Graphic Elements — public Layer 1 API
API v1 Data 2026-05-03 CC BY 4.0
STEALTH MODE

What is this?

This is the public, read-only API for the PTPGE taxonomy — an open vocabulary for the printing industry. Every term has a permanent URI, a definition, and SKOS-compatible relationships. Free to use under CC BY 4.0 with attribution.

Try it

The current version is at /v1/. Some example URLs to explore:

From the command line

curl https://api.ptpge.org/v1/scheme
curl https://api.ptpge.org/v1/manufacturing/standards/color-systems/color-spaces/cmyk
curl https://api.ptpge.org/v1/version

Format

All responses are JSON-LD — both human-readable JSON and a valid RDF graph. The JSON-LD context maps PTPGE-specific field names to standard SKOS and Dublin Core vocabularies, so the same data can be consumed by both plain HTTP clients and semantic-web tools (Skosmos, Protégé, Apache Jena, RDFLib, …) without any transformation step.

Compatibility option for plain JSON clients. Some tools and HTTP libraries don't recognise application/ld+json as JSON. Append ?format=json to any endpoint to receive the same payload with Content-Type: application/json instead — e.g. /v1/scheme?format=json.

Documentation

Full conceptual reference, layer model, SKOS mapping, and contributor guidelines are on the PTPGE Status Dashboard (internal access). The taxonomy sources are maintained in the canonical PTPGE repository.

Stability promise

Once a term is published, its URI is permanent. Approved terms are never deleted; they may only be deprecated, and deprecated URIs continue to resolve forever. See the PTPGE Four-Layer Model for the full guarantees and what is/isn't covered.