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RE: Font size

for

From: Jukka Korpela
Date: Jun 3, 2002 11:23PM

Leo Smith wrote:

> With regards to relative font sizes, I would recommend staying
> away from em units (the WAI recommends using them:
> http://www.w3.org/TR/WCAG10-CSS-TECHS/#units)

There are problems with em units, as well as % units, but all the
alternatives have drawbacks too. I'd rather accept the risks that long-term
solutions currently have than accept the problems that short-term solutions
have now and in the future, unless there is a strong difference in risk
levels (and there isn't here).

The usual caveats against em units relate to things like the effects of
careless use of em units with _nested_ elements and to some old browsers. A
cautious man would use just <small> and <big> in HTML markup, as suggested
in the famous
http://style.cleverchimp.com/font_size/livetext.html

> IE/PC appears to install with its font size setting to "smaller" or
> "smallest" in some cases.

Well, that needs to be fixed by the user if needed. It will surely cause
problems in normal browsing if the basic font size is too small for the user
to read, especially if it is so small that...

> If you use an em value less than about
> 0.95em, your copy will be unreadable - -

("Copy"? We're not considering the change of font size for copy text, i.e.
changing the _overall_ font size, are we?)

Accessibility doesn't mean designing for situations where the user's
browsing environment has been made unsuitable to the user's needs, in a
manner that could easily be fixed where the problem lies.

> The issue with em sizes and IE/PC seems to be that the
> "gradiations of change" between smallest, smaller, medium, etc
> font size settings are very large when em sizes are employed.

Pardon? How would those named sizes be affected by em sizes, or vice versa.

> Percentage based font sizes do not seem to suffer the same
> rendering issues.

Pardon? Isn't 0.95em exactly equivalent to 95%, for good or bad, by
definition?

> Alternatively, simply do not define font sizes at all.

That's naturally an option too. And almost always the only sensible option
for the _overall_ font size.

> In terms of using pixels, most new releases of major browsers do
> let you resize pixel based font sizes, IE/PC being the major
> exception.

Are you suggesting the use of px units, relying on the resizability in major
browsers, which seems like a bug to me? No matter how nice it would be to be
able to override, say, font-size:9px via a browser's font size menu, I don't
think that's _correct_ behavior. If I can do that, then my browser will also
resize _my_ px valued settings in my user style sheet, and that's
unproductive. When I say 9px, I mean nine pixels, nothing else.

--
Jukka Korpela, senior adviser
TIEKE Finnish Information Society Development Centre
http://www.tieke.fi
Phone: +358 9 4763 0397 Fax: +358 9 4763 0399


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