# pdfTeX warning: “version allowed”

After including some figures (saved as .pdfs) in my LaTeX document with \includegraphics, I got the following warning:

pdfTeX warning: pdflatex.exe (file ./figure/figure_1.pdf): PDF inclusion: found PDF version <1.6>, but at most version <1.5> allowed

The strange thing is, I'm using \includegraphics elsewhere in my document for other figures (also saved as .pdfs, in the exact same way), but no warning is generated for those.

What does this mean? How can I make it go away?

-
Can you please check what your pdftex.cfg for pdf_minorversion?Did you use the same same program for saving the files? Where did the image pdfs come from? –  Yiannis Lazarides Apr 17 '12 at 19:53
@YiannisLazarides I used the same program, savefig for MatLab, to save as .pdfs both the figures which generate warnings and those which don't... –  jamaicanworm Apr 17 '12 at 19:58
If I remember correctly Matlab uses ghostscript and there is probably a version issue. Set your pdfoptionpdfminorversion 6 and the error should disappear. –  Yiannis Lazarides Apr 17 '12 at 20:12
@YiannisLazarides: pdftex.cfg? pdftex hasn't used that file for ages. TL uses pdftexconfig.tex. –  Martin Schröder Apr 18 '12 at 6:30
@MartinSchröder Thanks. Need to do a memory refresh:) –  Yiannis Lazarides Apr 18 '12 at 6:34

By default, pdflatex will create a PDF version 1.5 file.

It seems that here one of your included PDF graphic is in fact in version 1.6 of the format and therefore has different features which will be lost in included in a pdf file of a previous version.

chances are that the graphic in question do not use any of the features available in PDF 1.6 but that is why there is a warning.

you can either recreate you graphics and if you have that level of control, make sure that it is saved in PDF v1.5, or you can raise the version of your output document to 1.6 by adding in your preamble:

\pdfoptionpdfminorversion=6


This depends on whether you have any restriction about the output document (some people insist on a specific PDF version).

-
Is there a reason the default is at version 1.5? Like, there might be problems in rare cases if I use 1.6 or something like that? Or is it just because of 3rd party requirements like you mentioned? –  lethal-guitar May 6 '13 at 20:48