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Re: Color Contrast

for

From: Simius Puer
Date: Jun 3, 2009 10:45AM

Hi David

The answer lies in the small print at the bottom of the WCAG.

*Large scale (text)*

[...]

*Note 2: *Font size is the size when the content is delivered. It does not
include resizing that may be done by a user.

*Note 3: *The actual size of the character that a user sees is dependent
both on the author-defined size and the user's display or user-agent
settings. For many mainstream body text fonts, 14 and 18 point is roughly
equivalent to 1.2 and 1.5 em or to 120% or 150% of the default size for body
text (assuming that the body font is 100%), but authors would need to check
this for the particular fonts in use. When fonts are defined in relative
units, the actual point size is calculated by the user agent for display.
The point size should be obtained from the user agent, or calculated based
on font metrics as the user agent does, when evaluating this success
criterion. Users who have low vision would be responsible for choosing
appropriate settings.
...now surely that is perfectly clear? ;)

Basically they have no entirely solid answer but for mainstream fonts "14
and 18 point is roughly equivalent to 1.2 and 1.5 em or to 120% or 150%" is
the key point that I believe you are looking for.

If you are in doubt of the end font size after you have applied numerous CSS
rules then I can recommend using Firebug (Firefox extension) or Dragonfly
(Opera extension) to determine the end size.