Create accessible PDF documents in InDesign

2.1 Use paragraph and character styles consistently

Please make consistent use of paragraph and character styles when formatting text. You can adapt and edit the styles as needed.

2.2 Manual breaks in text

Don¡¯t simply use hyphens to create word breaks. Instead, you should use the ¡°Discretionary hyphen¡± command, which is Cmd+Shift+- on a Mac and Ctrl+Shift+- on Windows. You can prevent a word from breaking by placing a discretionary hyphen at the beginning of the word using the same keyboard shortcuts.

2.4 Lists and numbered lists

Use the list function to create bulleted lists and numbered lists. Screen readers do not correctly interpret manually entered characters.

2.5 Hyperlinks and email addresses

Hyperlinks and email addresses can be created in InDesign by going to Window > Interactive > Hyperlinks. Enter the complete web or email address in the dialogue box and select the ¡°Hyperlink medium¡± style. Copy the address as alternative text into the field under ¡°Accessibility¡±.

3.1 Link all frames in a story

Be sure to thread all frames in a story together. Exceptions: Headlines and leads don¡¯t necessarily have to be linked to the text frames that follows.

4.1 Add all relevant frames to the story

To prepare for exporting the PDF, add all relevant frames to the same story in the Story panel (Window > Story). Create a story for each topic by clicking the framed plus symbol at the bottom of the Story panel. Use the plus symbol to add the text frames in the right sequence. The sequence can be corrected later by shifting the frames around.

Please note:

• If text is already threaded together, it¡¯s enough to incorporate the first text frame.
  
• Image frames that are anchored in the text don¡¯t need to be added (see ¡°Anchor images in text¡±).
• Be sure that the ¡°Use tag sequence for PDF with tags¡± option is selected in the Story panel.

5.1 Add alt text under ¡°Object export options¡±

If an image or graphic contains relevant content, it needs to have alternative text that describes what can be seen in the image or what information is contained in the graphic. You can compose alt text under ¡°Object export options¡± (via right clicking on the image). If an image or graphic has already been tagged with alt text, you can extract it via the XMP description function.

Tip:

You can use the InDesign text editor by pressing Cmd+Y (Mac) or Ctrl+Y (Windows). It¡¯s much easier to see the anchor position in this view as opposed to the layout view.  

Only use tables where they are unavoidable. Assistive technologies like screen readers have difficulty interpreting tables.

If you use tables, you should always use the InDesign table function and format the text using paragraph styles. Headers and footers must be defined as such using the table function.

In the file information window, the following information is the minimum that must be included in the Document Title field: ¡°Title of Document ¨C ETH Zurich¡±. Adding the author, description and keywords is also recommended, as PDF files on websites are indexed by search engines.

8.1 Detailed PDF settings

Select File > Export > Print PDF, click on ¡°Save¡± and fill out the settings. The following options must be activated:

• Export PDFs with tags
• Include bookmarks
• Include hyperlinks

Compression:

Recommended setting for images: 150 pixels per inch (medium image quality). ¡°Crop image data to frame¡± should be selected. The goal: the PDF should be as ¡°light¡± as possible.

Marks and bleed

Leave this empty; these settings are only relevant for printing.

Output:

Leave the settings as shown here (no colour conversion).

Expanded:

Select accessibility options ¡°Show document title¡± as well as the corresponding language setting.

9.1 Add PDF/UA identifier

Go to Edit > Preflight in Acrobat DC. Select ¡°PDF standards¡± and click on the screwdriver tool. You can add the PDF/UA identifier under Document Information and Metadata. Select this option and click on ¡°Correct¡±. You will now be asked to save the document again.
 

Open the PDF document that needs to be checked, select the accessibility tool and click on ¡°Check accessibility¡±. Don¡¯t make any changes to the dialogue box. Click on ¡°Start check¡±.

A report will then appear in the left column. If you have structured your article properly, as described in this guide, the structure will usually be displayed corrected. The most important error messages involve missing alt text or the missing PDF/UA identifier.

Note: If you use the templates provided and follow the steps in this guide, you¡¯ll be able to produce good quality accessible PDFs. If there are any small irregularities that get flagged in the report, try to correct them as far as possible. However, do not invest a disproportionate amount of effort. InDesign isn¡¯t error-free in this regard, and sometimes false positives are generated (e.g., untagged objects are reported even though everything was done correctly). ¡°Errors¡± of this kind do not impact the use of a screen reader in any appreciable way.