PDF/A in a Nutshell
The book about the new standard PDF/A by PDF/A Competence Center
The ISO standards PDF/A (ISO 19005) and PDF/X (ISO 15930) were developed for different purposes. However, many of the requirements of the two standards are exactly the same. The sections below explain the main differences between PDF/A and PDF/X.
PDF/A does not require – but does not forbid – the following technical print-related aspects that are required by PDF/X or are at least more common in PDF/X.
These aspects are required by the PDF/X standard but optional in PDF/A:
PDF/X-1a and PDF/X-3 forbid certain elements that are allowed in PDF/A:
PDF/A has more advanced requirements for metadata than PDF/X-1a and PDF/X-3:
Invisible text is often used for scanned pages to give a scanned page image text that can be used for OCR text recognition.
Important: There are separate output intents for PDF/X and PDF/A!
An output intent specifies the output purpose for a PDF file. Examples: A specific printing process such as sheet-fed offset on coated paper, printing on a specific type of digital printer, or output on the screen.
If a PDF/X file needs to be converted to PDF/A for archiving purposes without losing its PDF/X properties, this can be made particularly difficult if:
In most cases, the use of suitable tools such as pdfaPilot or Preflight in Acrobat Professional 8 should make it possible to save a PDF/X file as a PDF/A file without problems occurring.
If a PDF/X file needs to be generated from a PDF/A file without the PDF/A properties being lost, this can be made particularly difficult if:
In particular, problems can occur when attempting to store PDF/A documents that were not initially created for production printing as PDF/X files.