Color font issue (random scaling of glyphs) in Word and PowerPoint

Hi, I’ve made an extended colorfont (Latin Extended glyph set incl. kerning) with Glyphs which works well in design apps and browsers. When I’m in Word (16.46 on Mac OS 10.15) or PowerPoint and start typing, I get strange seemingly random scaling of some glyphs (see images) very frequently, sometimes all flips to the right size once I hit return to go to the next line. When I paste text all works well. I’ve generated the font as ttf and otf, with COLR/CPAL and/or SVG, all fonts appear to have the same issue in Word and PowerPoint.

Does that ring any bells?

@Jens Kutilek RoboChrome and the same issue happens there when I generate a ttf with COLR/CPAL. Only when I generate a ttf with SVG does the font perform as expected!



  • Thomas PhinneyThomas Phinney Posts: 2,704
    Does the strange scaling go away when you generate it as a plain non-color font?
  • Yes, the issue only occurs in the colorfont version of the ttf or otf.
    I'm wondering if the negative left & right side bearings (the underline element exceeds the width on either side) have anything to do with the glitch.
  • What flavour of colour font? COLR? SVG? 'sbix'?
  • Martin WenzelMartin Wenzel Posts: 48
    edited March 2021
    Hi @Peter Constable the issue occurs with the COLR version only. I have made many test but have not yet come to a conclusion why MS Office on Mac is misinterpreting the data. Something I did find out though is that Word does not like it at all when the width of a glyph is exceeded.
    (We don't need sbix, we're only interested in vector based color fonts)
  • @Peter Constable I'll gladly supply a demo font if you're interested
  • @Martin Wenzel I'll follow up with you in a private message.
  • @Peter Constable thank you, we'd very much appreciate that. You can get in touch with me at or via twitter (supertype_de).
    Ideally there is a solution that would allow users to exchange Word documents across platforms without having to switch fonts (from OpenType COLR on Windows to OpenType SVG on MacOS).
  • @Peter Constable & @Martin Wenzel, if you figured out what was the problem, I'd be interested in implementing a FontBakery check to automatically detect and report it.
  • @Felipe Sanches I have not yet figured it out but @Peter Constable is having a look at the issue.
  • bBox typebBox type Posts: 1
    Hi @Martin Wenzel
    Any news on this topic? Same happens here ...
    Thank you! Anja 
  • Hi @bBox type, I had some exchange with @Peter Constable but have not yet gotten an answer how this issue can be solved.
  • Hi @Peter Constable any update on the color font issue I had reported here? The bug persists in the latest update of MS Word on Mac (16.49, 21050901)
  • I reported this to engineers for Office. They were working on some higher priority issues, and then would be working on getting DWriteCore code converged for different platforms, at which point they could investigate this.
  • @Peter Constable thanks for the update, much appreciated.
  • Hello to everyone! I am joining to tell you that I have the same problem, but only for Powerpoint. MS Word does work fine.
    Do you have some kind of update for it?
  • @petrusenik Can you please clarify what OS/version and what versions of PowerPoint and Word you're using.
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