Issue with hinting in small sizes on Windows

Jonasss · January 30, 2023, 7:37pm

Hello!
What may be causing this misalignment at this specific point/pixel size?
The font looks descent at larger sizes, but at font-sizes smaller than 32px the glyphs are very weird looking (especially on windows). It is a hinting problem?

Windows 29px
29px

Windows 24px
24px

GeorgSeifert · January 30, 2023, 8:06pm

That looks like bad hinting or missed alignment zones. Is that an TrueType or PostScript based font?

mekkablue · January 30, 2023, 8:46pm

How are you hinting the font? TTF Autohint?

Jonasss · January 30, 2023, 9:32pm

It’s TrueType…
First I used autohint, then I did it myself, but the error persists. I don’t know why…

GeorgSeifert · January 30, 2023, 9:42pm

Can you show the outlines of “i” and “m”?

But if you get a similar result from auto hinting and manual hinting, then there is something wrong. Are you sure you disabled the “autohinting” in the export dialog?

Jonasss · January 30, 2023, 10:17pm

I made a copy and I work with this because I did a lot of adjustments trying to discover the error.

“Are you sure you disabled the “autohinting” in the export dialog?”
I’m not sure, I’ll try it this way.

GeorgSeifert · January 31, 2023, 7:10am

The baseline seems to match but the nodes at the x-height are not on the metrics line (they don’t have the brown diamond shape behind them). But that shouldn’t cause those issues.

Your overshot is quite big. It might be that the autohinter is confused by this. I’m not so familiar with the autohinting settings parameter if it can solves this.

mekkablue · January 31, 2023, 8:05pm

The screenshots show PS hints, not TT hints. They have no influence on TT Hinting.
This design does not lend itself for good overshoot suppression. The overshoots are simply too big. A rasterizer will only be able to suppress overshoots up to a relatively small size.
If your drawings are consistent enough (stick to the metrics and overshoots), you can try ttfautohint with optimized settings. See the ttfautohint tutorial.
Consider a gasp parameter.

Jonasss · February 2, 2023, 9:58pm

Thank you so much for your help! @GeorgSeifert @mekkablue
The problem was solved with the overshoot.
Also I used ttfautohint, woaa! it’s amazing!