Quality of webfonts, esp. on Windows

jaimes
jaimes Posts: 19
in Font Technology
So, I've been trying out many different webfonts for years.
One thing that is often a let-down is checking the rendering on Windows. I guess that's because of the disparities in the quality of hinting.

Is there any site/resource that reviews the quality of hinting and webfonts specifically?

For example, I find that Heldane Text renders quite iffy on Windows at sizes of 19/20px. Same with Sanomat Sans Text at sizes of around 17px.

By the way I find this on monitors of 2K resolution, as well as 4K resolution, so I don't think it's attributable to low-res.
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Best Answers

  • Thomas Phinney
    Thomas Phinney Posts: 3,063
    Answer ✓
    jaimes said:
    Thomas Phinney said:
    For extra fun, at all even vaguely normal sizes, Apple completely ignores the hinting info in the fonts.

    I thought Apple always ignored the hinting. Now I'm curious, when does Apple not ignore the hinting info? Super small sizes, I assume?
    Correct! IIRC it might be 8 px and below? Something like that. But not sizes that one typically views for reading most fonts and text. But can come up if one zooms out for preview purposes, or the like.
  • Mike Duggan
    Mike Duggan Posts: 243
    Answer ✓
    there is no resource as far as I am aware that reviews hint quality. If you have not seen it, this document I authored, goes into some detail on the various rendering and hinting methods https://googlefonts.github.io/how-to-hint-variable-fonts/

Answers

  • Thomas Phinney
    Thomas Phinney Posts: 3,063
    edited August 7
    Windows has like three or four different rendering modes, depending on your OS version and which API the app uses.

    These days the great majority of Windows apps are getting DirectWrite rendering (sometimes called “Natural ClearType,” but calling this ClearType is highly misleading—DirectWrite has abandoned the use of LCD-specific color subpixels which was the defining characteristic of ClearType as most people know it).

    However, if for example you are using Adobe Creative Cloud apps, in those AFAIK you are generally getting Adobe’s CoolType rendering engine, which is an entirely different thing (and cross-platform).

    Some web browsers on Windows can also get different rendering.  :smile:

    So... what OS version and apps are we talking about?
  • jaimes
    jaimes Posts: 19
    Ooof, complicated!

    Well I'm testing on Windows 11, and I've tried many browsers: Edge, Firefox, Vivaldi, all in their latest versions.
  • jaimes
    jaimes Posts: 19
    Kind of unexpected, but I'm finding rendering usually best in Linux. Avoids the extra thickness from macOS, and doesn't seem as aggressive with hinting as Windows.
  • Thomas Phinney
    Thomas Phinney Posts: 3,063
    For extra fun, at all even vaguely normal sizes, Apple completely ignores the hinting info in the fonts.
  • Andreas Stötzner
    Andreas Stötzner Posts: 821
    Jaimes,
    I do not want to submarine this conversation, but I would be interested to know how this typeface behaves in your test scenarios.
  • jaimes
    jaimes Posts: 19
    Andreas, I had a look, and it seems it renders well on Windows.
    That said, it usually takes a while of quotidian use for me to notice the subtle inconsistencies in rendering.
  • jaimes
    jaimes Posts: 19
    edited August 8
    Thomas Phinney said:
    For extra fun, at all even vaguely normal sizes, Apple completely ignores the hinting info in the fonts.

    I thought Apple always ignored the hinting. Now I'm curious, when does Apple not ignore the hinting info? Super small sizes, I assume?

    In my CSS I use the macOS hack:
    -moz-osx-font-smoothing: grayscale;
    -webkit-font-smoothing: antialiased;
    This brings the color in line with other platforms, but then the fonts can become a bit rickety, especially noticeable in light-text-over-dark background, or in light weights.
    I guess that hinting would have helped with that...

    Ah well, tradeoffs, tradeoffs.



  • mitradranirban
    mitradranirban Posts: 90
    Thomas Phinney said:
    ...
    These days the great majority of Windows apps are getting DirectWrite rendering (sometimes called “Natural ClearType,” but calling this ClearType is highly misleading—DirectWrite has abandoned the use of LCD-specific color subpixels which was the defining characteristic of ClearType as most people know it).

    But as per https://learn.microsoft.com/en-us/windows/win32/directwrite/introducing-directwrite direct write enhances LCD specific color subpixel " that enables it to evaluate not just the individual letters but also the spacing between letters"
  • John Hudson
    John Hudson Posts: 3,487
    edited August 8
    My understanding is that DirectWrite rendering makes use of subpixel distances, but is different from the original ClearType, which employed supersampling and asymmetric antialiasing at the subpixel level. The obvious effect of that was that text was antialised in RGB colour, which resulted in colour fringing to which people have varying sensitivity (hence the ClearType tuning tool that was part of Windows preference setup). DirectWrite rendering is using subpixel distances and rendering but resolving to greyscale.
  • jaimes
    jaimes Posts: 19
    So, with the churn in Windows, does it happen that a font had been well hinted for ClearType on a particular release, and later releases or technologies make the font render worse?
    Do fonts need periodic re-hinting to keep up?
  • John Hudson
    John Hudson Posts: 3,487
    Generally, no. Microsoft has a large collection of legacy fonts, including some that were intensively hinted for low-res pixel displays and printers. As rendering models and technologies change, MS is always trying to make sure that the older fonts continue to render well in new versions of Windows while maintaining the fonts as-is to support older versions.

    This has led to some controversial decisions. Notably, when ClearType subpixel rendering was introduced, Microsoft found that some of the very aggressive horizontal delta instructions used in hinting for low-res—i.e. hints that turn on or off individual pixels at specific sizes by shifting the outline in ways that often produced kinks—were rendering really badly in ClearType because the increased x resolution was revealing kinds and other distortions. So Microsoft’s solution was to disable x-direction delta instructions in the ClearType renderer, which of course limited the ways in which new fonts could be hinted for ClearType environments. At the time, there were a lot of lower- and mid-resolution screen still in use (120ppi and lower), so it would have been nice to be able to apply x-direction delta hinting targeting subpixel rendering.
  • Jens Kutilek
    Jens Kutilek Posts: 379
    John Hudson said:
    Microsoft’s solution was to disable x-direction delta instructions in the ClearType renderer, which of course limited the ways in which new fonts could be hinted for ClearType environments. At the time, there were a lot of lower- and mid-resolution screen still in use (120ppi and lower), so it would have been nice to be able to apply x-direction delta hinting targeting subpixel rendering.
    Maybe it was added later, but nowadays you can make x-direction deltas effective again by setting the interpreter to native ClearType mode using the INSTCTRL[], 4, 3 instruction.
  • John Hudson
    John Hudson Posts: 3,487
    Yes, that functionality was added a bit later, in response to complaints about the loss of x-direction deltas in the first release of ClearType. Initially, it didn’t seem to work reliably.

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