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Re: Question about px: Relative size?

From: David Woolley <david@djwhome.demon.co.uk>
Date: Thu, 21 Apr 2005 20:41:43 +0100 (BST)
Message-Id: <200504211941.j3LJfiw02586@djwhome.demon.co.uk>
To: w3c-wai-ig@w3.org

> browsers text size feature.  The pixels units do not allow that. So is =
> px "relative"?

For accessibility purposes, pixels should be considered non-scalable,
and should not be used.

I find the reference to their being relative confusing.  It comes about
because printer resolutions are much higher than screen resolutions, so
multiple device pixels have to be used for a single px.

In the relative sense, a px is about 1/800th of the screen width and
rounded to be an integral multiple (or exceptionally sub-multiple) of
the device pixel size.

However, I would argue that the more common definition of being about
1/96th of an inch rounded to a physical pixel is more a physical size.
Received on Thursday, 21 April 2005 19:41:47 GMT

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