Bold Cyrillics Serif Italics missing

[jugi1]

Cyrillic Italics for Bold Serif Libertinus are missing.
It is also in Biolinum fonts.

Is there a way to add it?
Thanks for supporting.

[khaledhosny]

They need to be drawn of course, which is something I have no expertise in doing (drawing Cyrillic glyphs).

[kiwi0fruit]

This is very dissapoining to see that bold italic cyrilic support is in "who knows" future... I know the fast way to add them. But they would be slightly in a miss-style. The best match for Libertinus that I found is PT Astra Serif. See how they fit together (PT means PT Astra Serif was used, Lib means Libertinus Serif was used):

For now the workaround is simply to have PT Astra Serif as a fallback font.

PS

As another temporal solution I made Libertin Serif/Libert Serif that are almost the same as Libertinus Serif but different:

• Libertin Serif doesn't have cyrillic characters at all. In other ways it's the same as Libertinus Serif,
• Libert Serif doesn't have bold-italic and semibold-italic styles. In other ways it's the same as Libertinus Serif. Chome/Chromium would automatically create bold style from italic on the fly,
• The best combination in case of css is Libertin Serif, Libert Serif fallback chain. In this case you would have original Linux Libertine bold and semibold italics for Latin and you would have Chrome-generated bold italics for Cyrillic.

Here you can see the quality of Chrome auto bold-italic from italic.

[kiwi0fruit]

Both workarounds are not ideal. The only right solution is to draw them all... Or adapt manually. Waiting for a hero :)

[kiwi0fruit]

More Deltails:

Cyrillic doesn't have bold italic. Cyrillic semibold italic is only slanted instead of real italic. PT Astra Serif (OFL) and Noto Serif (OFL) bold italic can be adapted to Libertinus Serif:

• Bold italic ж and л should be adapted from Noto Serif:
  • fix л like Libertinus bold r,
  • fix ж like Libertinus bold n, r, c,
• Bold italic к should be adapted from Libertinus greek bold italic κ, and normal italic к,
• Bold italic и, у, е, х, a, n, p, o, с, т should be taken from Latin (u, y, e, x, a, n, p, o, c, m),
• Other bold italic should be adapted from PT Astra Serif:
  • fix й, ц, ш, щ like Libertinus bold u,
  • fix н, ю like Libertinus bold n,
  • fix з, э like Libertinus normal italic з, э,
  • ъ should be adjusted or shortened may be,
  • fix ф like Libertinus bold j,
  • fix ы like Libertinus bold u, i,
  • fix я, ч, ь like Libertinus bold i,
  • fix м like Libertinus bold r, u,
• Take normal italic д from PT Astra Serif,
• Fix normal italic ж like c so it's more like bold italic from Noto Serif,
• From PT Astra Serif adapt normal italic я, м like Libertinus я, м.

A bit more info is here.

[StefanPeev]

@kiwi0fruit @khaledhosny Please, help me with your suggestions and notes and I'll do my best to draw Cyrillic Bold Italic and even the local forms for Bulgarian, Serbian and Macedonian scripts for all fonts in Libertinus family. You could see the first results at the Gallery. When I'm ready I'll ask you to help me to make a PR only for the final SFD file with the new and revised glyphs.
See also #122

[khaledhosny]

I can’t comment on the Cyrillic design, but please see the design guidelines if they are of any help.

[StefanPeev]

@khaledhosny Thank you! Design guidelines are very good! I hope that @kiwi0fruit or @KrasnayaPloshchad could give their comments. Soon I'll be ready for PR. The working variants are already seen at Gallery.

[StefanPeev]

This is an example how Libertinus Bold Italic looks in its Cyrillic version. There is a lot of work to be done still - for the glyphs design, for the metrics and kerning. If someone is curious to test the working version, I could share it through PR.

[kiwi0fruit]

My main idea was to adapt bold italic from PT Astra Serif - it was made by professional Russian typeface designer. Letterform can easily be reused because both Libertinus Serif and PT Astra Serif are of the same size as Times New Roman. And as I see it in your PDF example: ы, ь, ъ are better made in PT Astra Serif. I suggest using shapes from there (even regular italic) but adjust style - "ink dots" and serifs should match Libertinus style. I guess some other letters should be checked... I wrote adaptation spec somewhere above in this discussion but as you can actually draw glyphs it's useful only for checking which letterform design is better.

[StefanPeev]

Here are Libertinus Bold Italic and PT Astra. The structure of the glyphs is quite different.

[kiwi0fruit]

I also think that now ж lacks "ink dots". And э and г from PT Astra Serif has better form than from PDF (but э should definitely have wave-like inner part - difference is in thickening angles).

[kiwi0fruit]

Now э and г do not look neat. And ь, ъ, ы look alien to Russian texts.

[StefanPeev]

@kiwi0fruit Yes, it's true. But I just show you the moment picture of the work. I do not say the bold italic is done. There is a lot of work to be done still. However, the progress is not small. I will continue to edit glyphs and metrics, and when I think the result is much better, I will share the work file through PR.

[kiwi0fruit]

That's a very good start! :) I do not see anything more about glyph shapes for now.

[StefanPeev]

@kiwi0fruit I hope that it's a good start :) I see some problems in italic version also - but I'll do not touch it. Who made the Cyrillic italic version? It's a good idea if I could contact him - especially if he/she agree we to discuss the italics.

[kiwi0fruit]

I suggest fixing problems in italic version together with adding bold-italic (and don't actually forgetting about semibold italic). Do not touching regular italic would lead to the worse final result and even can add extra work of drawings bold italic twice (first now, then after fixing regular italic). But I do not remember heavy problems... Except letter л may be - something is wrong with it. Cyrillic italic was drawn by Linux Libertine author. Libertinus Serif is actually a maintained fork of LL with a bit more libre license (and more).

[StefanPeev]

@kiwi0fruit Alas there is no way to be made an interpolation between italic and bold italic with FontForge. Obviously the two styles are made absolute separately, which is not a good case - this is the reason the interpolation with FontForge to fail. I will try to prepare at least the Cyrillic version for interpolation with FontForge and thus we will have both good semibold italic version and compatable italic and bold italic version.
But it's a lot of work.

[kiwi0fruit]

I know about a lot of work. Luckily you are interested! But I think I understand your enthusiasm (even if can't draw glyphs myself) - Libertinus looks close enough to ideal finished result and it's beautiful.

[khaledhosny]

Fixed in ea760cc already.