PDF/X-6 Authoring and Validation

HotPDF supports complete, externally profiled, and N-colourant PDF/X-6 exchange workflows over PDF 2.0

Profiles

`PDFXCompliance`	`THPDFPDFX6Profile`	Output profile
`'X-6'`	`px6Complete`	Embedded ICC profile through `DestOutputProfile`
`'X-6p'`	`px6External`	External gray, RGB, or CMYK ICC profile through `DestOutputProfileRef`
`'X-6n'`	`px6NChannel`	External N-colourant profile plus matching `ColorantTable`
Detected from the document	`px6Automatic`	Uses the producer setting or loaded XMP identification

Complete profile example

PDF.Version := pdf20;
PDF.PDFXCompliance := 'X-6';
PDF.Title := 'Press-ready artwork';
PDF.Trapped := 'False';
PDF.BeginDoc;
PDF.CurrentPage.SetTrimBox(0, 0,
  PDF.CurrentPage.Width, PDF.CurrentPage.Height);
PDF.AddPDFXOutputIntent('CGATS TR 001',
  'Document printing condition', ICCStream, 4, 'DeviceCMYK');
PDF.EndDoc;

EndDoc runs fail-closed validation for all three PDF/X-6 profiles before serialization

Output-intent scope

AddPDFXOutputIntent adds one embedded Catalog-level profile for the complete profile
AddPDFX6PageOutputIntent adds an embedded profile to one page
AddPDFX6ExternalOutputIntent adds an external profile reference at Catalog scope with PageIndex=-1 or at page scope with a zero-based index
A page-level OutputIntents array overrides the Catalog array for that page
Each effective scope must contain exactly one PDF/X intent

Page boxes

The validator resolves inherited MediaBox and CropBox, checks direct BleedBox, TrimBox, and ArtBox values, and requires exactly one finished-page box per page

Every rectangle must contain four finite ordered coordinates
CropBox, BleedBox, and the finished-page box must stay inside MediaBox
TrimBox and ArtBox are mutually exclusive

Exchange constraints

One bounded graph traversal checks the profile identification and exchange structures while deduplicating shared resources by object identity

PDF 2.0 header, XMP profile marker, dates, title, trapped state, trailer ID, and absence of encryption
Action types, action chains, destination arrays, AcroForm state, and field additional actions
Printable visible annotations with fixed normal appearances and no PrinterMark or TrapNet subtype
Embedded font programs, Type 0 descendants, graphics-state value types and ranges, and resource XObjects
Disallowed page production-step data and alternate-presentation or viewer-preference Catalog data

Versioned rules

THPDFPDFX6ValidationOptions.RuleSet selects the published ISO 15930-9:2020 rules or the same edition with resolved errata through 2025-11-11, with the resolved-errata set selected by default

HPDFPDFX6RuleSetRevision returns the stable revision label, and every THPDFPDFX6ValidationIssue carries both RuleSet and RuleRevision so stored diagnostics remain attributable when defaults evolve

Painted colour, overprint, and transparency

The validator interprets graphics state and resources at actual paint operators rather than treating colour selection as painted output

Content-stream arrays share one q and Q stack, while each Form XObject applies its resources, matrix, transparency group and blending colour space at the invocation point
Paths, text, images, image masks, shadings, tiling and shading patterns, Type 3 glyph CharProcs, soft-mask groups and annotation appearances are traversed through their effective resource dictionaries
Empty paths, invisible or clipping-only text and unused Type 3 glyphs do not create painted-colour findings
ICCBased, CalGray, CalRGB, Lab, Indexed, Pattern, Separation, DeviceN and NChannel definitions are structurally validated before a paint is classified, including actual ICC header and component checks rather than trusting /N
Overprint mode 1 is checked only where component-preserving process paints can use it, and is reported as inapplicable for image and shading paints
Shading patterns begin from the enclosing content stream's entry state with transparency reset, and their pattern ExtGState applies only the nonstroking parameters used by the implicit sh paint
Combined fill and stroke is modelled as one implicit transparency group, with exact alpha equality and independent transparency or overprint policy gates
Soft-mask subtype, group and blending-space structure are checked before traversal; Alpha masks ignore group colour, while Luminosity masks require a valid group /CS and any /BC must contain one numeric value per blending-space component
Type 3 CharProcs require leading d0 or d1 metrics with exact operand counts, horizontal widths matching /Widths, zero vertical advance and ordered d1 bounds; d1 inherits the caller's colour while ignoring local colour and transparency operators and forbidding regular images but retaining image masks
JPX images without an explicit /ColorSpace use bounded header-only codestream colour metadata, cached once per image stream
When an annotation has a fixed appearance, /BM applies to the outer appearance composite, annotation /CA and /ca do not override it, and operators inside the appearance retain their own graphics state

Bounded execution and caching

Object, issue, decoded-byte, content-work, recursion and graphics-state-stack ceilings fail closed with stable diagnostics before unbounded allocation, including members nested inside TJ arrays

Decoded content, ICC profiles, JPX header colour and Type 3 structure use indexed document-local caches with geometrically grown storage, while context-sensitive colour and transparency state is re-evaluated for every invocation

Structured diagnostics

ValidatePDFX6 returns THPDFPDFX6ValidationIssues, an array of THPDFPDFX6ValidationIssue records whose THPDFPDFX6IssueSeverity identifies warnings and errors

Each issue includes a stable code, standard clause, rule set, rule revision, object path, object number, zero-based page index, and message

THPDFPDFX6ValidationOptions independently bounds objects, issues, decoded bytes and content tokens and can isolate output-intent, page-box, exchange, font, annotation, painted-colour, overprint, or transparency checks