When submitting a PDF file to the Research Collection please make sure

  • that your file is not write-protected
  • that fonts are embedded in the file
  • that you use only letters and numbers in the file name, i.e. no spaces, slashes, umlauts, etc. 
  • that you submit your file in the PDF/A format to enable its readabilty over the long-term. Below you will find instructions on how to create PDF/A files.

How to create accessible PDF files

ETH Zurich offers guidance and courses on creating accessible documents. You can find more information on the pages

1. What’s PDF/A?

PDF/A (/A stands for archive) is an ISO standard for the permanent archiving of formatted documents and should be readable for longer than more conventional PDF formats. The long-term readability of the PDF/A format is achieved by dispensing with certain functions and embedding all fonts in the file. A PDF/A file is recognisable by the blue bar in Adobe Reader.

2. Recommendation

  • We recommend using the subtype PDF/A-2b (b stands for basic) for saving new documents.
  • PDF/A-2u may be used if searching for special characters is particularly important (use the method with Adobe Acrobat Pro DC).
  • The PDF/A-1b Format is still recommended and older PDF/A documents do not need to be migrated.

3. Comparison of four conversion methods

Converting from MS Word or MS PowerPoint to PDF/A (or PDF) can be slow and can lead to loss of links and to errors in vector graphs, formulae, and special fonts. The following table shows pros and cons of four methods.





PDFMaker (recommended method)



Convert to PDF/A-2b or PDF (PDF/A-2u not available)

Adobe Acrobat Pro DC

Very Slow



Save as



References to footnotes no longer react to mouse clicks, but remain readable.

Converts to PDF/A-3a or PDF (no other options for PDF/A)

Adobe Distiller


Underlaid hyperlinks are lost

References to footnotes no longer react to mouse clicks, but remain readable.

Convert to PDF/A-1b or PDF, as conversion to PDF/A-2b is not available

4. Instructions for the four conversion methods

 PDFMaker (recommended method)

A Word or PowerPoint file may be converted to PDF/A-2b (or PDF) using Acrobat PDFMaker.

  • Open the document in Word or PowerPoint, select the Acrobat tab. (If the Acrobat tab is missing, your computer may only have free Adobe Reader software installed.4)
  • To convert to PDF/A-2b select “Preferences”. Then select PDF/A-2b in the dropdown menu “PDF/A Compliance” (once for each installation).
  • You may either select “Create PDF” in the tab “Acrobat” or “Save as Adobe PDF” in the tab “File”.1

 Adobe Acrobat Pro DC

A Word or PowerPoint file may be converted to PDF/A-2b (or PDF/A-2u, or PDF) using Adobe Acrobat Pro or Adobe Acrobat Pro DC.

  • Start Adobe Acrobat Pro DC and open your Word or PowerPoint File from within Adobe Acrobat Professional.
  • In the menu “File” you select “Save as …” and choose the desired file type PDF or PDF/A. To convert to PDF/A-2b select “Settings...” and “PDF/A-2b” with “sRGB”.

 Save as

A Word or PowerPoint file may be converted to PDF/A-3a (or PDF) by using Word or PowerPoint. We do not favour this option for creating PDF/A files, since we discourage using the subtype PDF/A-3a.

  • Select "Save as" from the "File" menu (not "Save as Adobe pdf").
  • Select "PDF (*.pdf)" for file type.
  • Select the underlined text “More options..”, then press button "Options...", then tick " PDF/A-compliant" to create a PDF/A file (subtype 3a with MS Word 365).2

You may create an identical PDF File by using Word or PowerPoint with the following commands:

  • Select “File” on menu bar, then select “Export”
  • Select “Create PDF/XPS Document”
  • Press button “Options..” and tick "PDF/A compliant"3

Adobe Distiller

If other methods fail because the document is large and complex, you may explicitly specify URLs of hyperlinks in the text and use the Adobe PDF printer (Adobe Distiller).

  • In MS Word or MS PowerPoint in the menu item "File" select the button "Print". Below "Printer" select "Adobe PDF". (If the "Adobe PDF" field is missing, your computer probably only has free Adobe Reader software installed4).
  • To create a PDF/A file, select "Printer properties". In the tab "Adobe PDF Settings", on the line "Default Settings" choose the drop-down menu item "PDF/A-1b: 2005 (RGB)" (PDF/A-2b not available).
  • Select "Print" to create the PDF file.

Check the quality of the PDF File

You should visually check the quality of the generated PDF file. Pay particular attention to formulas, links, special characters, transparent objects, and vector graphics.

5. Convert OneNote to PDF

When exporting directly from MS OneNote to PDF/A-2b (or PDF), those hyperlinks that are underlaid to the text are lost. To prevent this, you should first export the OneNote sections to MS Word. (Limit the OneNote entries to the page width first.) You can then convert the MS Word file to PDF or PDF/A-2b as described above.


1 The following website by Adobe gives further instructions (access date 4.3.2022)

2 The following website by MS Office gives further instructions to this method (access date 4.3.2022)

3 This method is also explained on the website of pdfa.org (access date 4.3.2022)

4 Only the method "save as PDF" does not require any paid software (Adobe Reader is free). The other three methods require licenced Adobe Acrobat products. Members of ETH Zurich can order Adobe Acrobat Pro DC from the IT shop (access date 4.3.2022). Please contact your IT support. See also the Adobe Acrobat XI: Product comparison (access date 4.3.2022).

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