Hinting's effect on Kerning and Letter Spacing

I’m currently testing out a typeface design in Adobe apps and I noticed that as I shrink down my type layers, the letter spacing seems to jump around. The letterforms themselves don’t change or distort, just the space between the letters.
Is this related to hinting? In other words, is it having to reposition the letters based on how many pixels are being used to display each letter. I guess I always assumed hinting could just help keep the shapes uniform, but I didn’t think letter spacing would be affected.
Would using hinting help with this problem? Or is it just the nature of displaying small type on a screen that you’re going to have issues with letter spacing?


You can’t hint the Y axis in Glyphs, so you can’t hint sidebearings. I doubt it would make a difference anyway. Adobe’s rasterizer just isn’t good at small sizes, probably becaue it’s a layout tool and not software for reading.

Are you exporting as .otf or .ttf?

Hints are not meant to preserve the shape of the glyphs. On the contrary, they distort them quite a bit to better fit them on the pixel grid. And that can lead to a but spotty spacing in Adobe apps. Try to export without hinting to see the difference.

I’m currently exporting OTF without hinting on. So I’m getting jumpy letter spacing even without exporting with hinting.
I tried exporting WITH hinting (and correctly setting up my hinting values and zones) and I actually see less spacing problems with hinting. But I do see some distortion of letterforms.
I guess I was mostly wondering if spotty letter spacing (without hinting) was fairly normal in a program like Illustrator. I just feel like I never really noticed it before or maybe its just because its a font of my own design so I’m noticing it more than I normally would.