Variable font bugs in Illustrator

Hey. I made variable font with 3 axes (width, weight, italic angle) and it have many bugs in Adobe Illustrator when test it. All contours matched between themselves, but in Black masters all inside roundings shift to straight corners (for Upright font). In Photoshop bugs start visible from 500pt.
Maybe you know how to make it better? *Kink Finder script did not help in this situation.

contours thin and black masters

variable font test in illustrator

This is visible when you move the slider, right?

Well, yes, if you interpolate from a contracted corner to a curve like this, you will run into situations like this, especially when it is very short. Consider perhaps an overlap construction, or perhaps bracket layers.

I saw bugs not only when use a slider, but in masters also have contour distortion. Like here - sharp corner appeared

The corner is a bug in Illustrator. What version of Glyphs do you have? The current cutting edge version might be able to work around it.

Now I use Version 2.6.1 (1230). I’ll try cutting edge version and report the result

Upd. Version 2.6.2 (1265) solved this problem

Maybe you know some way to avoid kink if I have situations like on screenshots - 1) point on diagonal segment with handles located on different sides of contour 2) diagonal straight line segment that rounds to horizontal line


Try to do without the point in (1).

Is (2) an AI screenshot again? Avoid hinting. Compare with browser display. If Irving’s shows in AI, it is likely an AI bug. Make sure you use the latest beta version of Glyphs. And: Are you using the Adobe Fonts folder?

Outlines on previous screenshot from Glyphs, black filled contours from Illustrator.

I use Version 2.6.2 (1265) and export ttf to Adobe font folder, font didn’t hinted.

How to test large size letters in browser?

There are a few options. All listed here:

I found another one bug.
If I have first letter with bracket layers and use it as component for second letter, then bracket layers in second letter didn’t work. In first letter all works fine)

If you just put the same bracket layers in the second component letter as in the first, then it works.

I tried that. It looks fine in Glyphs preview panel, but then I test *ttf in web browser and Illustrator - it’s not work