The Adobe spec for BlueValues states that
‘The first pair is the baseline overshoot position and the baseline. This is a bottom-zone.’
Tools I hav tested that output CFF fonts all seem to add a -20 0 bottom-zone to a font if the baseline zone in the source is not set exactly at 0, i.e. if it has an overshoot above as well as below the baseline, e.g. to catch an optically raised bar within the alignment zone.
Is it anywhere explicitly stated that the baseline is the mathematical rather than optical baseline? And if so, what is the best way to hint something that sits one or two units above the baseline that you want to align to the same height as things on or slightly below the baseline?
Tiro Typeworks
npub1rm…wuntj
2026-03-21 01:03:18 UTC
Author Public Key
npub1rmg092al9kzwfgzrv57jx3frhm2efcw4eu42n8hfswjewv3autuq0wuntjSeen on
wss://relay.ditto.pubPublished at
2026-03-21 01:03:18 UTCEvent JSON
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"content": "The Adobe spec for BlueValues states that \n\n‘The first pair is the baseline overshoot position and the baseline. This is a bottom-zone.’\n\nTools I hav tested that output CFF fonts all seem to add a -20 0 bottom-zone to a font if the baseline zone in the source is not set exactly at 0, i.e. if it has an overshoot above as well as below the baseline, e.g. to catch an optically raised bar within the alignment zone.\n\nIs it anywhere explicitly stated that the baseline is the mathematical rather than optical baseline? And if so, what is the best way to hint something that sits one or two units above the baseline that you want to align to the same height as things on or slightly below the baseline?",
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