PDF issue with WorkSans variable font
I'm getting a strange issue with the WorkSans static variable font when exporting a PDF. The font is from Google Fonts -- https://fonts.google.com/specimen/Work+Sans. The weight in the attached example is WorkSans Black. A strange overlap issue is happening in the crossbar of the A. The issue only seems to be occurring in that letterform. The only way I can seem to resolve this is by converting the font to outlines in InDesign, which is not ideal.
Thanks for reporting. We will review the issue shortly.
In regards to the OVERLAP_SIMPLE flag, find OVERLAP_SIMPLE at https://docs.microsoft.com/en-us/typography/opentype/spec/glyf
Here's a link to the .ttf https://drive.google.com/file/d/1bE9F8Gxf1w7DuUCY8R-KjpNWqgmZ5NmS/view?usp=sharing
Variable fonts are incorrectly filled when exported to PDF format on Mac.
Glyphs are shown without fault within InDesign itself (see vf_a_indesign.png). However, when exported to PDF format and opened on OSX, there is an issue with how overlapping contours are displayed (see indeisgn_a_pdf_mac.png). As you can see, where the contours overlap are not filled in correctly.
After some testing, we have identified this as an Adobe problem on macOS (the issue also occurs when we export Illustrator files to PDF). We believe the problem stems from InDesign and Illustrator subsetting the variable font into different static font instances, but not setting the correct overlap parameters during this process.
The reason the problem only occurs on OSX is that OSX expects static fonts to either have no overlaps, or the correct OVERLAP_SIMPLE flag in the glyf table, which Adobe apps are not setting correctly when subsetting variable fonts into static instances.
See the attached ttf (AktivGroteskVF_AOnly.tff) for reproducibility.