Creating & Evaluating Accessibility PDFs

Creating & Evaluating Accessibility PDFs

Evaluating Accessibility

  • The check accessibility tool marks when content doesn't have alternative text, but does not mark when alt text is incorrect.
    • Manual checks are needed.
  • If something is labeled as an error by the accessibility checker it is difficult or impossible to read and understand for people with disabilities.
  • If something is marked with a warning by an accessibility checker it is will most likely but not always impede the understanding of people with disabilities.

Creating PDFs

  • PDFs provide more robust accessibility information for accessible technology.
  • PDFs display / print more consistently across different platforms and devices.
  • Most documents will need further revision / modification and PDFs make that more difficult.
  • Creating PDFs requires some knowledge and paid software (Acrobat Pro).
  • Acrobat Reader is free and allows you to view PDFs.
  • Acrobat Standard is a paid program that lets you create PDFs and maintain the accessibility information of a source document.
  • Acrobat Pro is a paid program that lets you review and optimize the accessibility information.
  • Acrobat PDF Maker allows you to turn Word and PowerPoints into PDFs.
  • Never use the Microsoft Print to PDF function as it does not maintain accessibility information.
  • Do not convert a file to a PDF when saving it as this may not carry over the accessibility information correctly.

Optimizing PDFs in Acrobat

Optimizing PDFs

  • In the document properties tab on Acrobat, it will tell you what the application used to create the file is.
  • PDFs have three layers; visual, content, and tags.
    • The visual layer is what is seen on screen. It looks the same on whatever it is displayed on.
    • The content layer has basic information on text format and structure.
    • The tags layer defines the structures used to aid with assistive technology (headings, links, lists, tables).
  • Screen readers only have access to tagged content.
  • The order screen readers read them in is determined by the tag order.

Checking Accessibility

  • Run an accessibility check and review the report.
  • Logical reading order and color contrast must be reviewed manually.

Reading Order Tool

  • It's better to change the document's reading order in the source document rather than the PDF when possible.
  • When a document is exported to a PDF it may have tag structure issues.
  •  Marking content as an "artifact" in Acrobat Pro leaves it visible but removes the tag, meaning screen readers won't read it.
  • By default, headers and footers are not tagged.
    • Manually tag the footer text on the last page it appears on.

Content Order and Tags Order

  • Manually tagged content needs to have their tag order repaired.
  • Reflow allows content to be read on mobile devices or tablets.
  • Content order determines what order content is in when reflowed.
  • Only tagged elements are shown in reflow.
  • You can click and drag or copy and paste elements to move elements to their correct position in the order tree.
  • Verify order changes in the tags panel.
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