Inter 4.1: Saving as PDF from Word gives several issues

[mxxrten]

Describe the bug
In Word there are three ways to save to PDF, none of them work without problems with Inter 4.1.

1. Save as PDF. Inter.ttc works. InterVariable.ttf nothing is medium, semibold or bold:
   

2. Print to PDF with Microsoft Print to PDF. Inter.ttc italic gives weird characters:
   

3. Print to PDF with Adobe PDF. This doesn't output a PDF, but an error log:

%%[ ProductName: Distiller ]%%
Inter-Regular not found, using Courier.
%%[ Error: invalidfont; OffendingCommand: xshow ]%%

Stack:
-dict-
-file-


%%[ Flushing: rest of job (to end-of-file) will be ignored ]%%
%%[ Warning: PostScript error. No PDF file produced. ] %%
%[ Warning: PostScript error. No PDF file produced. ] %%

To Reproduce
Steps to reproduce the behavior:

• I use the latest Word version (Version 2501 Build 16.0.18429.20132) 64 bits
• I used the latest Inter 4.1 and installed Inter.ttc and InterVariable.ttf
• I type a few words in in the font Inter and Inter Variable.
• 1. File > Save as > PDF
• 2. File > Print > Microsoft Print to PDF
• 3. File > Print > Adobe PDF

Expected behavior
All fonts look as expected. A PDF file is made.

Screenshots
Screenshots are related to different steps. They are above in the relevant step.

Environment

• OS: Windows 11 Pro 24H2
• Word version (Version 2501 Build 16.0.18429.20132) 64 bits
• Inter Variable. Version 4.001;git-9221beed3
• Inter.ttc 4.1 (Fontdrop doesnt work with .ttc, but I downloaded it from the release page in this repo)

[kenmcd]

First, Word Export to PDF does not work with variable fonts.

Second, there does appear to be some odd conflict between the variable font and the TTC file. But I cannot see why.
With both the TTC and VF fonts installed I did see some garbage in the TTC static styles - three were garbled - and not the same ones as yours.
So I uninstalled the VF fonts - and the Word Export to PDF was just fine with just the TTC.

Oddly, LibreOffice (LO) has problems with the TTC, alone or with the VFs installed.
The Bold style-linking is not working - there is some odd conflict.
So I un-installed the TTC and installed the separate static fonts, and then LO was working fine.
Extracted the separate TTFs from the TTC file, and installed those, and those also worked fine in LO.
So perhaps something funky in the TTC structure.

Both Word and LibreOffice also work fine with the separate static fonts (from the extras folder).

I re-installed the VF fonts, and Word is still working with the TTC installed.
So I cannot figure-out what is going on.
The TTC (or separate statics) should not conflict with the VF fonts.
But the complexity of the names in the VFs may confuse some applications.

So for now, probably best to use just the TTC or separate statics alone, without the VFs.

[mxxrten]

@kenmcd Also with InDesign 2025 export to PDF I get a warning in Acrobat Reader:

Tested with 4.10 .ttf and .ttc

[kenmcd]

That probably means that embedded sub-set font is corrupted - like the displays above.
If possible, I would like to see that PDF.

I think I may have found what is confusing Word.
Going to modify the variable fonts and test.
Gonna take a few days (have other things that must get done).

[mxxrten]

@kenmcd I'm using Inter in our new user manuals, here is part of that user manual. Weird is that with all the weights at the top left the weights themselves look fine. Let me know if you need screenshots of this PDF, but I expect you will see the same with Adobe Acrobat Reader Pro latest version (2025.001.20435).

Test PDF: inter test.pdf

[kenmcd]

Interesting. On my phone at the moment...
That PDF looks fine in multiple PDF readers and editors on my phone.
But, the PDF viewer in my phone file manager app does not show the Regular and Italic styles.

Lots of applications have issues with TTC files.
I assume ID has no problems with the separate static font files.

Hopefully I can look at this PDF later today on my laptop using more powerful tools to see what ID did.