E-mail List Archives

Re: PowerPoint accessibility-alt question


From: Olaf Drümmer
Date: Apr 30, 2014 2:53AM

Hi Bevi,

sorry to disagree with some of what you state… (and apologies for making it even more difficult for some on this list to understand fonts any better).

Anyways, here goes my summary:

[1] Let's distinguish between
- fonts embedded in PDF
- fonts embedded in EPUB
- fonts used for authoring (whether Word, PowerPoint, OpenOffice, Indesign or whatever else)

[2] Fonts in PDF
- always embed
- it doesn't matter what type a font is once it is embedded in PDF, as long as it is embedded correctly (good ole' PostScript Type 1 fonts can be just fine, and mighty be encountered even if an OpenType fonts was used for authoring; actually, in many cases OpenType fonts will actually be embedded as trueType or PostScript Type 1 fonts, without any loss of functionality or quality)

[3] Fonts in EPUB
- EPUB is a very muddy area when it comes to devices and programs that present them, and how they use fonts
- many EPUB readers use their own built-in fonts anyway
- where EPUB readers do actually use embedded fonts, OpenType and TrueType are your best bets

[4] Fonts used during authoring
- Microsoft doesn't support PostScript flavoured OpenType fonts as well as it does support TrueType flavoured OpenType fonts
- Adobe and Apple can handle any font type equally well
- with maximum cross platform in mind (e.g. for office applications) use TrueType flavoured OpenType or TrueType (almost always the filename suffix will be .TTF)
- the difference between TrueType flavoured OpenType and plain TrueType is mostly in functionality (e.g. addressing special or alternate characters in a font, advanced ligature like character combinations in foreign scripts, …), but not in Unicode support

If we were to make a distinction regarding authoring between "user communities":
- if you are in the office world, use TrueType flavored OpenType or TrueType
- if you are in the layout and graphic design world, use any OpenType or TrueType font

Disclaimer: there are fonts that are good, and there are fonts that are not so good - regardless what type they come in. Most fonts that come with recent versions of operating systems or applications from Adobe, Apple, and Microsoft are usually pretty good.

And by the way - old fonts are often available in today's operating systems for backward compatibility.


On 30 Apr 2014, at 04:38, Chagnon | PubCom < <EMAIL REMOVED> > wrote:

> There is one heck of a lot of misinformation in that online forum thread!
> https://discussions.apple.com/thread/2803119 No one seemed to know the
> details about fonts.
> Summary for the WebAim original poster:
> 1) Use only OpenType fonts on Macs and Windows.
> 2) Stop using TrueType and PostScript fonts, both are deprecated font
> technologies since 2000. They lack extended character sets which contain
> many characters that will help accessibility. Plus, they lack some key
> technical requirements for today's publishing technologies, such as EPUBs.
> FYI, OpenType fonts can have up to 64,000 characters and are based on a
> standardized, universal Unicode character set. That means better
> accessibility now, and definitely in the future. Hopefully it will minimize
> all those strange characters AT users run into in documents.
> 3) On the Mac, don't use dFonts as they too present problems in EPUBs and
> accessible technologies.
> 4) Always always always embed your fonts into the PDF. Did I mention always?
> 5) OpenType fonts come in 2 flavors: TrueType and PostScript. For practical
> purposes, this means absolutely nothing. As long as the font is OpenType, it
> will be OK to use. The TrueType and PostScript flavors mostly just define
> the original source code of the font. Example, Microsoft's fonts were
> originally TrueType so their OpenType versions are OpenType/TrueType.
> Adobe's font were originally PostScript so their OpenType versions are
> OpenType/PostScript. As I said before, this doesn't affect accessibility or
> making PDFs. In fact, I haven't seen it affect anything whatsoever except
> for producing a lot of hogwash on Internet forums. So use OpenType,
> regardless of the flavor.
> 6) TrueType fonts have the file extension dot TTF. OpenType fonts can have
> either dot OTF or dot TTF. Therefore, you can't always tell if you're using
> an OpenType font or not. Sighted users can see a blue-green O icon next to
> the font name for all OpenType fonts, both TrueType flavored and PostScript
> flavored. A blue TT icon appears next to TrueType fonts.
> 7) Recent operating systems from both Apple and Windows ship with
> industry-standard OpenType fonts. Windows also includes a handful of old
> TrueType fonts, and Apple ships with a handful of dFonts, neither of which
> should be used to make accessible documents or EPUBs. I do not have a good
> reason why these 2 companies still ship their operating systems with
> out-of-date fonts.
> 8) The Calibri font mentioned in the forum is part of Microsoft's Cleartype
> font collection that were developed specifically for better legibility and
> readability on computer screens. They are installed with MS Windows and
> Office, so they're fairly well distributed on Windows systems. And they are
> in OpenType format.
> That was probably more than you ever intended to know about fonts! Being a
> former typesetter many decades ago, I couldn't give just a quick
> explanation.
> -Bevi Chagnon
> - PubCom.com - Trainers, Consultants, Designers, and Developers.
> - Print, Web, Acrobat, XML, eBooks, and U.S. Federal Section 508
> Accessibility.
> - 508 Workshop: www.workshop.pubcom.com
> - US Federal Training: www.gpo.gov/customers/theinstitute.htm
> -----Original Message-----
> [mailto: <EMAIL REMOVED> ] On Behalf Of Duff Johnson
> Sent: Tuesday, April 29, 2014 5:12 PM
> To: WebAIM Discussion List
> Subject: Re: [WebAIM] PowerPoint accessibility-alt question
>> On the subject of Mac OS conversion of Word/PowerPoint files to PDFs,
> we've noticed another problem that is related (I think) to the unicode font
> issue - i.e., the PDF rendering wants to use unicode font and if it can't
> find a font set that matches the one in the original document, it
> substitutes different symbol and letter combinations for some characters in
> the resultant PDF. This can make some words unintelligible if you're
> listening to the PDF with a screen reader.
>> In our experience, it seems to happen most frequently with PDFs that are
> created on a Mac. We would love to give instructors and faculty members some
> simple instructions on how to avoid this problem - does anyone has any
> guidance on which fonts to use and which to avoid when creating MS Office
> documents on a Mac?
> The issue is: fonts must be embedded when the file is created. This applies
> for files created on any platform.
> For the Mac, this thread provides some tips to addressing the issue:
> https://discussions.apple.com/thread/2803119
> I hope this helps.
> Duff.
> > > messages to <EMAIL REMOVED>
> > >