Glyphs completely ignores OpenType features in imported typeface

I have recently been exploring the possibilities of OpenType by importing typefaces with Glyphs and looking through the features tab. For the first time, I have found a font with features that Glyphs haven’t been able to import. It is called Mars Fraktur and is made by Diplomingenieur Gerhard Helzel over at
The features work fine in the programs I have tested them in (including Illustrator and InDesign) and are properly imported with FontForge. As far as I know, it contains what seems like a hardcoded list of words for its “smart” long s (ſ) substitution (really thorough with hundreds of lines). I don’t know if that is the problem, or the fact that it was generated with a 2007 copy of Macromedia Fontographer. Either way I hope someone can cast some light on the issue.

Because it is one of the site’s trial fonts, I have linked it here for further inspection.

The font at that link appears to have been generated by FontForge 2.0 on May 11, 2018. Previously it was generated by FOG 4.1.4 in April 2007.

For more information on why the feature import likely failed, please read this:

I see. Perhaps a problem with the way FontForge compiles the features, then. I still think it is interesting how none of the code could be recovered. Makes me doubt the OpenType format somewhat.

I’ll have a look.

There where two issues. The first was easy to fix. The second is a bit more complicated. The font uses context substitution lookups and almost all tools that are used to produce OpenType fonts never write them (fontForge seems to be the exception here). Because of this, there are almost no fonts using those lookups and thous tools can’t implement it because without test date this is difficult. I tried OTMaster from URW and they ignore those lookups, too.

The good thing is that now I have some test data and can fix this.


Sounds good. Thanks for looking into it!

I improved it. But it is still not 100%.