- From: Daphne Preston-Kendal via GitHub <noreply@w3.org>
- Date: Mon, 12 Jan 2026 11:33:53 +0000
- To: public-css-archive@w3.org
At least in the implementations I have tried, `font-optical-sizing: auto` simply sets `opsz` to the point size of the font automatically. The typeface designer typically designs the optical sizes for print, not for the screen. Even on modern high-DPI displays, there sometimes needs to be some compensation for the coarseness of the medium. Look at the linked [Bodoni](https://indestructibletype.com/Bodoni.html) page, for example – for the body test, the designer of the font, to show it off, selected an optical size of 6 (using a font file with this setting rather than `opsz`, in this case) although the calculated font size (based on a default browser stylesheet) is 20.8px. Even for the headings `h2`, he selects optical size 24 with a calculated font size of 128px. If the approach here could be browsers using some more intelligent strategy to pick a value of `opsz`, that would be great, but it would need to take account of the design of the font as well as the particular screen; it’s likely a problem about as hard as that which is solved by e.g. ttfautohint. -- GitHub Notification of comment by dpk Please view or discuss this issue at https://github.com/w3c/csswg-drafts/issues/13331#issuecomment-3738121649 using your GitHub account -- Sent via github-notify-ml as configured in https://github.com/w3c/github-notify-ml-config
Received on Monday, 12 January 2026 11:33:54 UTC