W3C home > Mailing lists > Public > www-style@w3.org > December 2009

Re: Redesign Styles Hypocritical

From: Gérard Talbot <info@gtalbot.org>
Date: Mon, 30 Nov 2009 21:57:36 -0500
Message-ID: <834472bafe638ce1b36bc5de81d9a1f2.squirrel@cp3.shieldhost.com>
To: "Ian Jacobs" <ij@w3.org>
Cc: "James Hopkins" <james@idreamincode.co.uk>, "Felix Miata" <mrmazda@earthlink.net>, "www-style@w3.org" <www-style@w3.org>, "site-comments@w3.org" <site-comments@w3.org>

> It is my current understanding that
> the default font size is an area of debate.


Regarding CSS, accessibility, WCAG 1 and WCAG 2 (guidelines, checkpoints,
techniques, examples, tips, related resources, explanations, etc), it does
not seem to be an area of debate. So far, I have read many webpages coming
from w3.org domain and everywhere, every single place, I read that
- absolute unit for font size (like "px" and "pt") should be avoided
- large fonts by default (for unstyled body content) should be provided or
should be preferred
- scaling font sizes smaller than the user-agent default should be avoided
or should be carefully thought over

Web Content Accessibility Guidelines (WCAG) 2.0
Guideline 1.4 Distinguishable: Make it easier for users to see and hear
content including separating foreground from background.
1.4.4 Resize text
http://www.w3.org/TR/2008/REC-WCAG20-20081211/#visual-audio-contrast-scale

How to Meet WCAG 2.0
A customizable quick reference to Web Content Accessibility Guidelines 2.0
requirements (success criteria) and techniques
1.4 Distinguishable: Make it easier for users to see and hear content
including separating foreground from background.
Resize text 1.4.4
Sufficient Techniques for 1.4.4 - Resize text
http://www.w3.org/WAI/WCAG20/quickref/#visual-audio-contrast-scale

Resize text:
Understanding SC 1.4.4
http://www.w3.org/TR/UNDERSTANDING-WCAG20/visual-audio-contrast-scale.html


"
When font size is specified in any absolute units of measurement, such as
points or pixels, the Text Size menu commands in Internet Explorer 7 and
earlier do not resize the text.
"
coming from C12: Using percent for font sizes
http://www.w3.org/TR/2008/NOTE-WCAG20-TECHS-20081211/C12.html

That is still [and also] true for Internet Explorer 8. It's not just IE7
or IE6. So that particular issue with IE will be around for 5-10 years at
least. [Addendum: on top of everything, there is no minimum font-size
setting which can be conveniently and quickly set in Internet Explorer 8,
in Internet Explorer 7, etc.. ]


"
In Internet Explorer 6, using ems for font sizes will cause the text to
grow more than using % or named font sizes. So, text-size/largest, might
cause the text to grow more than 200% and have clipping problems.
"
coming from C14: Using em units for font sizes
http://www.w3.org/TR/2008/NOTE-WCAG20-TECHS-20081211/C14

That is also true for Internet Explorer 7. That C14 document implicitly
suggests that such bug was fixed in IE7 but it is not the case.


There is another inaccuracy in C28 btw:
Em units for sizes for layout container containing text
will fail in a bunch of CSS columnar webpage template cases in Internet
Explorer 6 and Internet Explorer 7. So, that particular example is not
ideally recommendable.


"
Use scalable rather than absolute units.
 * Use em, percent(%), or keywords.
    Try not to use pixels (px) or points (pt) for font and block sizes
because the user cannot resize them.
"
coming from Accessible CSS
http://cookiecrook.com/AIR/2003/train/accessiblecss.php


"
The font size of display characters is expressed in relative size and not
absolute size.
"
coming from Optquast Best Practice N°4 - Level 2- Section accessibility
http://en.opquast.com/bonnes-pratiques/fiche/4




> On the question of color contrast, we've stuck with a grey text for
> now, which I believe is WCAG 2.0 AAA compatible.


G17: Ensuring that a contrast ratio of at least 7:1 exists between text
(and images of text) and background behind the text
http://www.w3.org/TR/2008/NOTE-WCAG20-TECHS-20081211/G17.html

That page provides a list of online web applications
http://www.w3.org/TR/2008/NOTE-WCAG20-TECHS-20081211/G17.html#G17-resources
to test the author stylesheet and provide the "relative luminance of
letters and text" algorithm.


> That choice is purely
> stylistic, and again, I realize it will not satisfy all users.


It must be first of all a matter of compliance with G17 before it can be
considered a purely stylistic issue.


> Thanks for sending comments. I welcome the feedback,


>From a strict demographic perspective, people over 40 or over 50 or with
mild, small, average visual disabilities or mild, small, average visual
loss are demographically growing proportionally speaking in the western
world and their representation will be growing furthermore in the next
10-20 years.

People over 40 or over 50 or with mild, small, average visual disabilities
or mild, small, average visual loss are not best served by a standard body
like W3C promoting an awkward "font-size: 13px" when, on the other hand,
browser manufacturers all have been defaulting their browsers to
"font-size: 16px" expressed in a manner that is scalable, resizable and
relative in the last 15 years.


>>> Is it really possible to meet WCAG 2.0 while
>>> setting font sizes in px?

No, it is not possible.


Gérard Talbot
Received on Tuesday, 1 December 2009 02:58:19 GMT

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