Subject: (resend) Re: [css-d] ems or percent?

From: joel.young at ns.sympatico.ca (Joel Young)
Date: Mon, 28 Apr 2003 09:09:39 -0300

(I think the email below may have gotten lost in the shuffle
over the weekend, so I'm resending it.
If I've broken any etiquette by doing so, I apologize.)

At 09:20 PM 4/26/03, Mike wrote:
><snip>
>On the basis that it's impossible to please all users at all times, what, in
>your opinion(s) and in ems or %, is the best body/menu/heading/text font
>settings "standard" to suit most browsers, on most platforms, for most
>users, most of the time?
>
>Mike
>Edinburgh, Scotland

Yes! This is what my original question was about, and I'm glad you brought 
it back around, Mike. Hopefully someone will have an answer for us. In the 
meantime, let's see if I understand a few things.  Someone please tell me 
if I'm even close to knowing what I'm talking about.... :-)

===============
Scenario 1:
Assume that I start my page off like this: body {font-size: 80%}

This means that all text on the page will be rendered only 80%
of the browser's default. Yes? No?
===============
Scenario 2:
body {font-size: 80%}
.classname {font-size: 1em}

All text on the page will still be 80% of the browser's default,
because basically 1em = 100%, and I'm only setting it to 20%
less (which is 80%).  Right? Wrong?
===============
Scenario 3:
body {font-size: 80%}
.classname {font-size: 0.9em}

Okay, NOW the text will actually be just under 80% of the
browser default, because it is 9/10ths of 80% of default.
===============
Scenario 4:
body {font-size: 80%}
.classname {font-size: 100%}

Again, the text remains at only 80% of default, because I've
set it to be 100% of the body font size (not that I would do that,
it's just for example)
===============
One more... Scenario 5:
body {font-size: 100%}
.classname {font-size: 1em} or {font-size: 80%}

Here, the text will either be the full browser default, or 80% of it.
Right?
===============

If all the above are correct, then it's just as easy to set the body at
100% all the time, and simply use smaller percentages for different
sizes.
That, or do body {font-size: 100%}, and use various em sizes, and
everything should work out - keeping the sizes within a reasonable
range, of course.

Did I reach home base, or am I somewhere in left field?

Joel

---

From: akuehn at nc.rr.com (Adam Kuehn)
Date: Tue, 29 Apr 2003 15:59:56 -0400

This is a non-flame-war aspect to this problem, so I'll answer.  Yes, 
your reading is correct on this point and all the points that follow, 
with one caveat: be clear that "browser's default" refers to the 
person doing the browsing, not the piece of software.  As has been 
thoroughly discussed, the individual may have changed his or her 
settings, so what they see may not be the same as what the browser 
ships configured to display.  So long as you are aware of that 
possibility, you have calculated resulting sizes correctly.

You have to decide for yourself if it is more important to cater to 
the cognoscenti or the clueless.  Just be aware that whichever group 
you pick, the other group will see something different when it comes 
to font size.  Also, it is pretty much universally acknowledged that 
the clueless is by far the larger group.

<opinion type="strongly held">
My own view is that it is better to be concerned more about 
accessibility and less about aesthetics.  Text that is slightly too 
small is less easily accommodated than text that is slightly too 
large.  In addition, my experience is that more users back out of 
sites with text they find too small than sites with text they find 
too large.  This is the primary - and contrary to popular belief, 
carefully-considered - reason that browser makers have chosen font 
size defaults rather on the large side.  Take care in overriding 
their judgment.

In any case, be extremely sure of your choice if making non-header 
font sizes greater than 150% or less than 75-80% of the default 
*anywhere* on a site.  Sizes outside that range are virtually assured 
of irritating some of your users.  (That is, constructions like your 
third example, which made the inner text 72% of the "browser's 
default", should generally be avoided.)
</opinion>

-- 

-Adam Kuehn