Requirements for PDF creation

Minimum standards for long-term readability and availability must be observed for publication on OPUS.

With seven checks to the finished file

A PDF (Portable Document Format) is not equal to a PDF. Not all PDF files are suitable for publishing on OPUS. Consider the following seven requirements to get a long-term archivable document:

The text to be published is machine-readable and barrier-free, i.e. the text must not be embedded as a graphic. It is searchable, markable and can be copied.

OPUS is a publication server that makes all publications permanently freely accessible on the Internet (Open Access). Therefore, the PDF files must not contain any password protection. Only then they are suitable for long-term archiving.

  • The images embedded in the PDF (pixel-based photographs, graphics) should not be unnecessarily large. Instead of using 10 MB image files, 500 KB are often sufficient.
  • The images should not be compressed too much (e.g. recognizable by blurriness, artifacts on lines or distorted colors).
  • Vector graphics should be preferred because of the small memory size.
  • For the publication the necessary copyrights or rights of use are available, which are in accordance with the OPUS licensing terms.
  • The rights of use are proven in the list of figures and if possible also directly at the picture (name of the author, source, license).

The fonts used in the PDF are embedded. All fonts used should appear in the document properties, usually in the "Fonts" or "Types" tab (slightly different menus depending on the PDF viewer).

The document properties should at least contain information about the title, author and keywords related to the content (metadata). Additional information such as language or license information is desirable. The information should also match the document.

At least the headings of the first level of the document should be bookmarked. This allows easy navigation through the file.

For qualification theses, the curriculum vitae, the declaration of originality, and the like do not belong in the publication. Most importantly, original scanned signatures should be avoided. Please check carefully what personal information you really want to disclose.

To ensure long-term digital archiving, the publication should be in PDF/A format. It is recommended to submit as PDF/A-2a. As an alternative are also accepted:

  • PDF/A-2b
  • PDF/A-2u
  • PDF/A-1b
  • PDF/A-1a

PDF files with embedded audio and video content are not suitable for long-term archiving (PDF/A).

Detailed instructions

Conversion to PDF/A is now possible directly from many text editing programs. Alternatively, you can find some conversion tools on the Internet that can be downloaded and used.

More detailed instructions for PDF creation:

Validate PDF/A with pdfforge

Name a file

At the end, it is important to also assign a meaningful file name:

University of Stuttgart Library


Open Access Team

Holzgartenstr. 16, 70174 Stuttgart

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