pdf/a: Width information for rendered glyphs is inconsistent

Question

Have there been any advances to create a valid pdf/a-1b from LaTeX including math fonts? I get the following error from preflight in Adobe Acrobat Pro: Width information for rendered glyphs is inconsistent for the document (TeXLive 2011 and PDFLaTeX):

\documentclass{article}

\usepackage{MnSymbol}
%\usepackage{mdsymbol}
\usepackage[a-1b]{pdfx}

\begin{document}

\begin{equation}
  \sum
\end{equation}

\end{document}

For this to run, a sRGB profile is needed which can be downloaded here. Rename it to sRGBIEC1966-2.1.icm.

Next to fixable errors (e.g. no metadata supplied), I get the error for either MnSymbol or mdsymbol. Is there something to be done in the mf source code? Any other advice? Unfortunately, Acrobat cannot fix this issue.

Answer 1

I cannot provide an LaTeX-based answer, but I tried the new Acrobat Reader XI in order to get a fully valid pdf/a-1b document from your MWE. Et voilà, it worked well, the pdfwidth information for rendered glyphs was also fixed. One drawback though, in comparison with Acrobat Reader 9 the generated files seem to get larger.

Answer 2

I'm sure you're no longer interested in the answer, but for future readers who happen upon this thread:

Can you avoid using the MnSymbol or mdsymbol packages? When I use the amsmath package instead, I have no problems. The appearance of the characters is slightly different, but I suspect that's not a problem for most applications. My code is:

\documentclass{article}

%\usepackage{MnSymbol}
%\usepackage{mdsymbol}
\usepackage{amsmath}
\usepackage[a-1b]{pdfx}

\begin{document}

\begin{equation}
  \sum
\end{equation}

\end{document} 

It seems like the basic issue is that some of the characters in the two symbol packages you are trying to call (including \sum) have zero character width, which violates the ISO standards for PDF/A documents. The characters called by the amsmath package evidently don't have this property.

This problem is poorly documented, but I found these two sources which are obliquely related:

tug.org/pracjourn/2010-1/beccari/pdfatricks.tex

and the last section of

http://support.river-valley.com/wiki/index.php?title=Generating_PDF/A_compliant_PDFs_from_pdftex

Answer 3

To solve problem like this, but with \textnumero sign often used in russian (or all cyrillic) texts (T2A fontenc encoding) and cm-super|cmr font in pdflatex, i used code:

\UndeclareTextCommand{\textnumero}{T2A}
\usepackage[safe]{textcomp}

I can not say that i understood what i was doing. I was inspired by answer about \DeclareTextSymbol. I think you can use something like this to redefine math symbols also.