PDF/UA, PDF/A, PDF/X

Accessible, archival and print-ready files: the engine writes what a claim requires and keeps it, or refuses it with the reason.

curl https://api.reflowpdf.com/v1/pdf \
  -H "Authorization: Bearer $REFLOWPDF_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{"html": "…", "options": {"pdf_a": "3a", "pdf_x": {"output_intent": "FOGRA39"}}}' -o print-and-archive.pdf

// one file: accessible (PDF/UA-1), archival (PDF/A-3a) and print-ready (PDF/X-4)
const pdf = await reflow.pdf.create({ html, options: { pdf_a: '3a', pdf_x: { output_intent: 'FOGRA39' } } })

# one file: accessible (PDF/UA-1), archival (PDF/A-3a) and print-ready (PDF/X-4)
pdf = client.pdf.create(html=html, options={"pdf_a": "3a", "pdf_x": {"output_intent": "FOGRA39"}})

What each claims#

Option	Standard	PDF	For	Plans
`pdf_ua: 1`	PDF/UA-1 (ISO 14289-1)	1.7	Accessibility: the structure in reading order, headings, lists, tables with their headers, alternative texts, the language and the title. Every tagged PDF is written to it.	all
`pdf_ua: 2`	PDF/UA-2 (ISO 14289-2)	2.0	The same on PDF 2.0, with its structure namespaces.	Pro, Max
`pdf_a: "3a"`	PDF/A-3a (ISO 19005-3, level A)	1.7	Archiving: every font embedded, colour defined by an output intent, XMP metadata, tagged (with PDF/UA-1); attachments as associated files.	Pro, Max
`pdf_a: "1b"`	PDF/A-1b (ISO 19005-1, level B)	1.4	Archives that accept only PDF/A-1: transparency flattened to opaque images, text kept selectable and searchable.	Pro, Max
`pdf_x: { standard: "x-4" }`	PDF/X-4 (ISO 15930-7)	1.6	Print: the press's characterization as the output intent, trim and bleed boxes, every font embedded; transparency and RGB kept for the press to convert.	Pro, Max
`pdf_x: { standard: "x-1a" }`	PDF/X-1a:2003 (ISO 15930-4)	1.4	Presses that take only X-1a: all colour converted to the condition's CMYK inks, transparency flattened.	Pro, Max

Check a file yourself with veraPDF, the PDF Association's reference validator for PDF/UA and PDF/A. The engine is developed against it.

Which go together#

Together	Allowed	Why
`pdf_ua: 1` with `pdf_a` or `pdf_x`	yes	PDF/UA-1 is tagging; it holds in any of them. `pdf_a: "3a"` carries it.
`pdf_a: "3a"` + `pdf_x` X-4	yes	One PDF 1.6 file, archival and print-ready.
`pdf_a: "1b"` + `pdf_x` X-1a	yes	Both PDF 1.4, without transparency.
`pdf_a: "1b"` + `pdf_x` X-4	no	PDF/X-4 keeps transparency; PDF/A-1 allows none.
`pdf_a: "3a"` + `pdf_x` X-1a	no	PDF/A-3 is PDF 1.7, PDF/X-1a PDF 1.4.
`pdf_ua: 2` + `pdf_a` or `pdf_x`	no	PDF/UA-2 is PDF 2.0; neither is.
`encryption` + `pdf_a` or `pdf_x`	no	An archive or a print file opens without a password.
`attachments` + `pdf_x` or `pdf_a: "1b"`	no	Their standards forbid embedded files.

A pair that cannot go together is 400 invalid_request, before anything prints.

Print conditions#

A PDF/X file names the press it is made for: its output intent, the ICC characterization of the printing condition (the paper and process) that colours are meant for. Name one the API has:

curl https://api.reflowpdf.com/v1/output-intents -H "Authorization: Bearer $REFLOWPDF_API_KEY"

const { data } = await reflow.outputIntents.list()   // [{ id: 'FOGRA39', info, color_space: 'CMYK' }, …]

for c in client.output_intents.list().data:
    print(c.id, c.info, c.color_space)

output_intent	Profile	Printing
`FOGRA39`	Coated FOGRA39 (ReflowPDF), built from Fogra's FOGRA39L data	Offset on coated paper, ISO 12647-2:2004: the common condition in Europe
`CGATS21-2-CRPC5`	CGATS21-2-CRPC5 (ReflowPDF), built from ISO 15339-2 data	Typical publication coated (ISO/PAS 15339-2): the successor of SWOP in North America
`CGATS21-2-CRPC6`	CGATS21-2-CRPC6 (ReflowPDF), built from ISO 15339-2 data	Typical premium coated (ISO/PAS 15339-2): the condition of GRACoL
`CGATS TR 001`	U.S. Web Coated (SWOP) v2 (Adobe)	Web offset on coated paper, SWOP as of 1993: still named by many North American printers

Or bring your printer's own: its ICC output profile (class prtr; gray, RGB or CMYK; up to 8 MB) in profile, base64, named by output_intent (the name is written as the file's OutputConditionIdentifier):

import { readFile } from 'node:fs/promises'
import { base64 } from '@reflowpdf/sdk'

const pdf = await reflow.pdf.create({ html, options: { pdf_x: {
  standard: 'x-1a', output_intent: 'PSO Coated v3', profile: base64(await readFile('PSOcoated_v3.icc')),
} } })

import base64

profile = base64.b64encode(open("PSOcoated_v3.icc", "rb").read()).decode()
pdf = client.pdf.create(html=html, options={"pdf_x": {"standard": "x-1a", "output_intent": "PSO Coated v3", "profile": profile}})

PDF/X-1a prints in process inks only: its condition is a CMYK one.

When a document cannot keep a claim#

A claim is kept or refused, never written over a file that breaks it. When the document itself stands in the way, the response is 422 unfulfillable and detail says what:

{
  "type": "https://api.reflowpdf.com/docs/errors#unfulfillable",
  "title": "Not possible for this document",
  "status": 422,
  "detail": "PDF/X cannot be claimed for this document: the document keeps transparency that flattening could not remove (PDF/X-1a allows none)",
  "code": "unfulfillable",
  "request_id": "req_x7Kq2mVb9TcA3pLw"
}

Nothing is counted for it. On a plan without the claim, the response is 403 plan_required.