typoascender_exceeds_Agrave

Checking that the typoAscender exceeds the yMax of the /Agrave.

typoascender_exceeds_Agrave

• Applies to: TTF
• Fontspector can hotfix?: no
• Fontspector can fix sources?: no

Rationale

MacOS uses OS/2.sTypoAscender/Descender values to determine the line height of a font. If the sTypoAscender value is smaller than the maximum height of the uppercase /Agrave, the font’s sTypoAscender value is ignored, and a very tall line height is used instead.

This happens on a per-font, per-style basis, so it’s possible for a font to have a good sTypoAscender value in one style but not in another. This can lead to inconsistent line heights across a typeface family.

So, it is important to ensure that the sTypoAscender value is greater than the maximum height of the uppercase /Agrave in all styles of a type family.

Proposal

• https://github.com/fonttools/fontbakery/issues/3170

Profiles

• universal (in section 'Universal Profile Checks')

• googlefonts (in section 'Universal Profile Checks')