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Re: Do fonts have to be embedded in a WCAG 2.0 conforming PDFdocument?

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From: Duff Johnson
Date: Apr 15, 2015 7:38AM

OK, some background...

Embedded font programs allow software to correctly reproduce all glyphs without reference to external resources.

To answer Patrick's question: embedding ensures reliable presentation of the document's text because the viewer is not forced to substitute fonts that may not match the usage specified in the document.

The lack of embedded fonts can cause a range of issues varying from (merely) an unintended ugly appearance to total illegibility.

So font embedding clearly applies to Principle 1.

Font embedding is also necessary for Unicode mapping of text, affecting adaptability and reuse, and allowing recovery of semantic properties for each character of the textual content.

So font embedding clearly applies to Guideline 1.3.

>> What is your understanding of this point? Does WCAG 2.0 require font embedding in PDF documents, or not?
>
> It really depends on if when the font is not embedded a success criteria is not met.

But which SC? The issue seems to fit the high-order requirements (Principles and Guidelines) more than any specific SC.

> If you can show a case such as a failure of SC 1.4.4 Text Resize when fonts aren't embedded then I think there is a good case for it.

A viewer that substitutes fonts due to a lack of embedded fonts might still be able to resize whatever text it managed to display, but its functionality would be just as unpredictable as a viewer that was not trying to resize text.

> Otherwise it would be difficult to argue unless there is some other SC such as 1.3.1 which might apply to font attributes not being available such as underline, bold, etc. as there are few semantic tag equivalents to this communicate this information.

In PDF, underline is indicated (for accessibility purposes) by an attribute called TextDecorationType, which may be applied irrespective of font embedding.

Duff.