How to reduce horizontal shifting/"wiggling" characters caused by autohinting?

Hi friends,

I’m in the process of proofing spacing and when I zoom from wide to close-up (in Illustrator in the video linked below), many of the characters shift or wiggle back and forth horizontally in a really abrupt way that causes some awkward spacing inconsistencies.

The screen recording is on a Dell external monitor with a resolution of 2560 x 1440, so it’s not a Mac Retina display, and a smooth zoom-in will not be a common scenario many end-users would prioritize, but this highlighted what (I’m guessing) the auto hinting is doing to adjust spacing at smaller sizes.

Is the amount of horizontal shifting/wiggling normal? Is there anything I can do to reduce the severity of this shifting and make spacing more consistent across all sizes?

And I’ll just mention, the wiggle may look small in the recording, but on a large screen, it’s quite noticeable.

Currently, I have a few hints applied manually, but much of the typeface is relying on the autohinter.

Any suggestions/advice on how to address the issue would be appreciated!


That’s normal. It’s just how the Adobe rasterizer works.

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Thanks! That’s helpful to know in general - I tested out a variety of other retail and system typefaces with a similar result but less “wiggle” in general… I was able to improve the stability of the characters by adding manual hints where the autohinter didn’t apply them but it’s still shaky and inconsistent.

If you have a strategy regarding where/when you add vertical hints I’d appreciate any suggestions. Thanks!

I don’t add any manual hinting to PS fonts. The way I see it Adobe users are used to stuff shifting around as they zoom so I don’t worry about it.

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If you want shaping consistency, don’t hint. Unhinted outlines will be rendered with more antialiasing, and thus appear more consistent.

Hinting is about distorting the outlines into the pixel grid, in order to preserve minimum legibility at low pixel sizes by achieving a sharper image (less antialiasing). It does that at the expense of shape consistency. When you zoom in or out, the ppm size will change, and of course the fitting will cause shifts. Zooming in and out is not what hinting is optimizing for. It is instead optimizing for legibility at specific sizes. Since testing usually doesn’t happen much while zooming (or the other way around, users are not expected to zoom a lot while they are reading), that’s to be expected.

You need to decide if you want to optimize your outlines for legibility at low resolution or for shape consistency while zooming. In the latter case, I recommend to ditch hinting altogether.

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This is the reason why the Apple text rendering is not applying hints. Because they do care about consistency when transforming (zooming, rotating).

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Fascinating - shape consistency is definitely the top priority as the intended use case for the typeface here is headline/titling rather than extended text.

I seem to still have a lot of inconsistency in letter spacing at small sizes and assumed it was a lack of vertical hinting that was allowing the characters to “slide” back and forth. For example, there are instances where the space between letter pairs is different enough that the pair begins crashing into one another in one case while a clean separation is preserved in other cases. (Screenshot below - this is from InDesign 10pt type viewed from 125% then zoomed in to show differences)

I also find letters like Y and T, which should be symmetrical, are rendered differently where the stem is offset to the right or left in a noticeable and undesirable way.

Some/all of these issues may be the result of screen resolution (again, this is not on a Mac retina display), but is there any way to reduce the severity of these issues or make the modifications applied in the rendering process more consistent? From your responses, it seems like removing as many hints as possible may actually help?

My theory was that applying hints manually would at least make the modifications more consistent but maybe it causes more problems than it helps… The main goal is consistency, if the letters begin to crash into one another or are altered significantly at a certain size that’s OK, I’d just prefer those changes to be the same for the shape/outlines of the same letter or spacing between the same pair of letters.

Thanks again for your help!

I just re-read the PS auto hinting Tutorial and with regards to the inconsistent counters of the H’s it sounds like that’s not the intended effect of hinting - to quote the tutorial

“This is an enlargement of the same n typed several times. You can see that the first two n’s have a counter of 4 pixels, while the following n’s show a counter of 5 pixels. That is OK…”

That makes sense, but any other suggestions on achieving improved consistency in lettershapes and spacing would be great.

I’ll keep experimenting - thanks!