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Correction, or update needed?

From: Linda A. Walsh <w3@tlinx.org>
Date: Sun, 24 Apr 2011 16:47:34 +0000
Message-Id: <4DB09FBC.4070204@tlinx.org>
To: site-comments@w3.org
I wasn't sure where to send this, since the group responsible for the page has been disbanded, so I'm hoping you'll know where to direct this...



I did a google search to find out about default font sizing.

One of the pages that came up was:
http://www.w3.org/QA/Tips/font-size

By my understanding, there is a minor, but important "bug" on this page that should be corrected.

About mid-page, there is a section "Units: avoid absolute length units for screen display".

Under that the first sentence of the first bullet point says:


"Do not specify the font-size in pt, or other absolute length units for screen stylesheets. "

This statement concerns me since people might think they should substitute 'px', instead, which, IMO, is worse, and 'pt' is more easily resizable as it's not *really* (in practice), absolute.

If they use 'pt', I can  compensate by setting my "DPI" value,  and in that sense, "pt" is really a relative unit, as it is relative to the "DPI" value.  Theoretically, it should be a non-issue if the DPI was always set correctly for a given monitor,  however, the 'pt' really equal to 1/72 of the value in "DPI".  I.e. if DPI is set to 72, then 1 pt=1 dot (or pixel), but if DPI is set to 144, then the PT is equal to two dots.

This is especially important "today", since to resize one's display on Win7, MS resets the DPI value to a higher number -- meaning it's not really the number of dots/inch, but a scaled value.

Of course in HTML5, even 'px' is scaled, but that's even farther in the future (as far as being widely adopted as a standard).  

One could argue that since 'px' is no longer based on the hardware size of a pixel (in HTML5), that maybe 'pt' should also be redefined toward some more useful definition, like 1/12th or 1/16th of 1EM?

Anyway, the advice as written stuck out to me as 'wrong' (even though, by definition it is not) since in practice the DPI value is now used as a way to rescale not just webpages, but entire displays and most certainly, I've always preferred sites that use 'pt' vs. 'px', since the 'pt' value honors my DPI setting, whereas sites that use 'px', often appear too small (especially when I was using a laptop with a 144DPI screen, *ouch*!)  Now, my monitor is nominally 100DPI, but most text still appears too small, so I generally use a 120DPI value.
Received on Monday, 25 April 2011 14:00:50 GMT

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