Kerning pairs: is there a maximum amount?

I am totally new in making fonts and I hope to find an answer here or some tips regarding my issue. I want to develop a hand drawn font. My crossbars are curvy and quite elongated beyond the vertical stems. For this reason, I made a lot of kernings. My question: My uppercase alphabet (without numbers, accents, interpunctuations and lower case letters) has about 90 kerning pairs at present. I tested my uppercase letters with many example texts and I am pretty happy with the result but is it the case that this high number of kerning pairs may pose a problem when I go on like this? Should I delete all my kerning pairs and start again from the start with spacing (and avoid kerning as much as possible?).

I am really thankful for your remarks.
Best regards from Vienna

Yes. There is a maximum amount. It is not an amount of pairs though, it’s more complex. You will typically hit the ceiling after you cross 2k, 3k or 4k pairs.

Best is to optimize your spacing (left and right sidebearings) in such a way that you need as little kerning as possible.

I recommend you read both the Spacing and Kerning tutorials.

Ok. Thank you very much!

So I will start again :slight_smile: I did not know that you have tutorials here. Thank you for the recommendation.

Glyphs makes class kerning quite accessible and goes a long way to reducing overload problems.

Thank you very much!

It should be a uint16 value pairSetCount in the GPOS table so the maximum amount is 65536 (it’s tooooo large for a normal font).

The problem is that group-glyph and glyph-group kernings must be dissembled to individual glyph-glyph kern pairs. And one kern pair takes more than 1 byte, unfortunately. So it is way less than 64k.

On the good side, only the beginning of the kern subtable must be in the 64k limit. And you can have more anyway if you enable the Use Extension Kerning parameter.

But if you need that much kerning, the spacing is probably really bad.

Once again thank you very much for all the helpful info. I have individual glyph-glyph kern pairs for my hand drawn brush stroke sans serif alphabet of uppercase and lowercase letters (plus numbers, symbols, etc.).
I use Glyphs version 2.6.1. Where can I enable the Use Extension Kerning parameter? By the way, are there any basic Font Making Workshops in Vienna :slight_smile:

Latest version 2 is 2.6.6 (stable) and 2.6.7 (beta) I believe. I recommend updating.

Every once in a while. Yes. :slight_smile: I am doing one right now every Friday morning.

Where do I find these morning workshops? Is there a schedule or an agenda? Are they via zoom?

They are for a school and in German, you can join with MS Teams. Please send me your email address.

I sent you my email address via email. Hope you received it so I can have the link for your presentation on Friday. This would be great.
I have now updated my glyphs version to 2.6.6 / Under which menu can I enable the Use Extension Kerning parameter? I also searched for this in the Help section without any results.