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Re: [csswg-drafts] [css-fonts] Proposal to extend CSS font-optical-sizing (#4430)

From: Chris Lilley via GitHub <sysbot+gh@w3.org>
Date: Mon, 28 Oct 2019 16:32:22 +0000
To: public-css-archive@w3.org
Message-ID: <issue_comment.created-547031612-1572280341-sysbot+gh@w3.org>
> From this result, it appears that the size of a typographical point is different between Windows and macOS / iOS. This is a very interesting result, and I didn't realize it or try on Windows when implementing this.

I think this dates back to the original Mackintosh (and Lisa?) which had 1/72 inch pixels, specifically so that 1 pixel would equal 1 point. This was way before CSS redefined SI measurement units :) and is also the source of the oft-quoted and wildly anachronistic "screen resolution is 72ppi, printers are 300 ppi" (from the original LaserWriter). 

It isn't the case on other systems though, which is why CSS eventually settled on the `1in = 2.54cm = 96px` definition in V&U, largely for Web compat reasons.

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Received on Monday, 28 October 2019 16:32:23 UTC

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