Justification alternates

Hi there,

I am working on designing a Hebrew typeface. I have created alternates that are horizontally elongated. Is there a way to have them automatically used to help with justification?

(I know a lot about letters, and very little about coding! Sorry if this question is phrased in a way that makes no sense!)

Thank you!

There is a justification table in the OpenType spec but no apps support it, yet. @SimonC is experimenting: https://twitter.com/simoncozens/status/1202215566280409090

As Georg said, there is currently no way for a layout application to automatically apply justification features. Putting things in the JSTF table is one option, and in theory it means that your font will have justification alternates enabled whenever applications do get around to supporting it - but I am not convinced that they will, because there are various problems with the JSTF specification anyway.

Depending on what you want to do, another option would be to release the font as a variable font with the expanded glyphs available via the GEXT (glyph extension) axis. You can see some examples of GEXT axis fonts here, and I have implemented justification via GEXT axis for Armenian fonts in the web browser using my newbreak justification engine. (Because the Armenian font was not a free one I don’t have an example of that online, but it does work - see the Arabic demo for a similar concept which uses the width axis rather than GEXT.)


InDesign (and one other macOS application its name escapes me), support using glyph alternates from the jalt feature for justification and it is probably good enough for Hebrew. jalt is a simple alternate substitution feature like salt, so probably can already be done in Glyphs.

Hi Khaled! Thank you so so much!

It seems to me like this feature just automatically swaps out any glyph for a jalt version of that glyph, irrelevant of the justification. Am I missing something? Is there a way for it to only use the jalt glpyhs occasionally when it is necessary for the justification?

Thank you again!

Are you enabling the feature manually? It should be automatically enabled by the applications (that support it) as needed when justifying the text. In case of Arabic see https://research.reading.ac.uk/typoarabic/on-arabic-justification-part-2-software-implementations/

Please can you share more details on how to achieve the justification shown in the samples using variable font.

Not sure what more details you want. If you have a variable font, you can achieve the justification by following the instructions on https://github.com/simoncozens/newbreak

For some reason, I can get this to work for existing fonts, but not my own. My glyphs are named like this “tav-hb.jalt” (tav is the letter name, hb is hebrew) and I have justification alternates enabled in InDesign. Any idea what is going wrong? Thank you so much again!

Hi there,

Reopening this discussion because I was fiddling around with the jalt in my design and I too couldn’t get them to work on Illustrator and InDesign.

Does jalt require JSTF support?
Based on my understanding, and from khaled’s response above I don’t think it does.

Also is there anyway to have multiple alternates for a single glyph? If so, what would the syntax look like?

Thanks a ton!