Generating PDF/A compliant PDFs from pdftex

Introduction

This page describes necessary steps to create PDF/A compliant PDFs from pdftex and related issues. When we compile a latex document with pdftex, there can be a few issues that can prevents the result from begin pdf/a compliant, such as:

• problems with fonts:
  • font files are not embedded,
  • mismatch of character widths,
  • characters of zero widths,
  • fonts don't have a ToUnicode mapping
• problems with metadata:
  • XMP data not included,
  • XMP data don't match the info in pdfInfo catalog.
• problem with interword spacing: pdftex don't use space to separate words in pdf output.
• problem with color data.

The usual way to verify if a pdf file is pdf/a compliant is to use a validating tool. There are a few pdf/a checking tools; the most common one is the Preflight tool in Acrobat Professional version 8 or newer. Beware that these checking tools can give very different the result on pdf/a compliance of a given pdf: a pdf file that passes pdf/a compliance checking in acrobat 8 can still fail to pass a check by another tool. In this document, we assume the following:

• input are latex documents
• tex live 2008 (which includes pdftex version 1.40.9) is used for latexing
• Acrobat 8.0 for pdf/a validation

We start by a minimal example, and then move to more complex ones, to illustrate the issues one may encounter when trying to achieve pdf/a compliance.

A minimal example

Let's have a minimal document hello.tex that looks as follows: <geshi lang="latex"> \documentclass{report} \begin{document} Hello, world! \end{document} </geshi>

When we compile it with pdflatex and check for pdf/a compliance, we will get a report like this: