Comment 19 for bug 1555109

Btw., the fonts that I've checked in FontForge (Oswald and Montserrat) all had weight class values that were multipliers of 100 (so the 'multiple of 50 issue' that mikmikmik mentioned shouldn't be the reason of the problem. At least not the problem I had).

Also: The workaround from the following bug report (linked above) doesn't seem to work (if I understand it correctly):

https://bugs.launchpad.net/inkscape/+bug/1655512

The author mentioned that it's possible to add the name of the font style to the font name - so instead of 'Montserrat' you would put 'Montserrat Thin' into the field of the font name.

If you do this, Inkscape puts a small warning sight besides the font name with the title "Font not found on system".

The result is that Inkscape substitutes the font ('Montserrat Thin') for something different ('sans-serif' in my case).