RE: Making pt a non-physical unit

For the record, IE treats “pt” the way you propose for a number of versions already. At this time there is no physical units in IE (that is there is no unit that doesn’t grow or shrink with zoom) .

New units have been proposed that would be defined as strictly physical (I believe somebody has proposed “dpx” for “display pixel”). Such proposals haven’t picked up much, perhaps because any physical unit will likely be accidentally misused, and any use case that really requires a physical unit has a script workaround.

From: www-style-request@w3.org [mailto:www-style-request@w3.org] On Behalf Of Robert O'Callahan
Sent: Tuesday, January 05, 2010 3:06 AM
To: www-style
Subject: Making pt a non-physical unit

My understanding from a conversation I had on #webkit is that Webkit avoids the problem by treating 1pt as 4/3px regardless of the display DPI. I think we probably need to do this in Gecko for Web compatibility reasons, and so for the sake of honesty in Web specifications, I propose that the definition of pt in CSS be altered accordingly.