PDF/A is an ISO document-archiving standard designed to guarantee long-term readability. In this blog entry, we show how to convert documents into PDF/A-1b format in accordance with the ISO standard.
What’s a PDF/A format?
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 subtype PDF/A-1b (b stands for basic) is used the most frequently. The long-term readability of the PDF/A1b format is achieved by dispensing with certain functions on the one hand and embedding all the objects required (e.g. fonts) in the file on the other. A PDF/A file is recognisable by the blue bar in Adobe Reader.
While attempting to convert a Microsoft Word or Microsoft PowerPoint document into a PDF or PDF/A, links are frequently lost or formulae and graphics displayed incorrectly. What can be done to prevent this?
We tested four different conversion methods based on ten example files to investigate their features. We explain their pros and cons in the following instructions.
- “Printing” a file as PDF
A file can be sent to a PDF printer in Word or PowerPoint, which is often the best method for elaborate documents. The drawback, however, is that highlighted links are lost.
Select the “Print” button in the “File” menu in Microsoft Word or Microsoft PowerPoint, where you can choose the option “Adobe PDF” in “Printer”. (If the “Adobe PDF” field is absent, most likely only Adobe Reader is installed on your computer. In this case, you should install Adobe Acrobat Pro or opt for one of the other methods.) Select the field “Printer properties”. Open the “Standard settings” dropdown in the “Adobe PDF settings” tab and click on the menu item “PDF/A-1b: 2005 (RGB)” (Figure 1). Then click on “Print” to create the PDF file.
Figure 1: Set standard settings to PDF/A-1b
- Creating a file using Adobe Acrobat Professional
This method takes time to convert large documents. The conversion procedure: open the Word or PowerPoint file with Adobe Acrobat Professional, select the menu item “Save as…” in the “File” menu and choose “PDF/A”. In the next window, you determine the file name, the storage place and the button “Settings…” In another window, select the option “PDF/A-1b” and “sRGB” (Figure 2).
Figure 2: PDF/A-1b can be selected under settings
- Saving a file as PDF/A-1b using Acrobat PDFMaker
This method takes time to convert large documents and can even fail completely.
Open the Word or PowerPoint file, select the “Acrobat” menu and choose the option PDF/A-1b in the basic settings (once for each installation, Figure 3). You can then create the PDF document either in the “Acrobat” menu with the “Create PDF” menu item or in the “File” menu with the “Save as Adobe PDF…” menu item.
Figure 3: PDF/A-1b can be selected under basic Settings
- Creating a file in Word or PowerPoint using “Save as”
The drawback of this method is that vector graphs are frequently unusable and links in footnotes are lost.
Select the option “Save as” (not “Save as Adobe pdf) under the “File” menu and then PDF format. Select “ISO19005-1-compatible PDF/A” under “Options…” (Figure 4).
Figure 4: Select “ISO19005-1-compatible PDF/A” under “Options…” (ISO19005-1 is PDF/A-1; the file created fulfils at least PDF/A-1b)
Conclusions: no method is perfect
As we can see, every method has its pros and cons. In each case, you should check the PDF/A file created closely. Pay particular attention to links, vector graphs, formulae and special fonts. Further information on these four methods is provided in the PDF/A-1b document “Conversion of Microsoft Word or PowerPoint Files to PDF/A-1b” in the Digital Curation Office Downloads on ETH-Bibliothek’s Knowledge Portal.
This work is licensed under a Creative Commons Attribution-ShareAlike 4.0 International Public License.
DOI Link: 10.16911/ethz-ib-2722-en