I've installed an open source typeface, which comes with different weights from thin up to black. When browsing installed fonts with, say, Fontmatrix, all weights are properly shown. Same is true when I select any of the font weights in a libre office application. However, graphic tools like GIMP and Inkscape lack at least one of the installed typeface weights. It's always the thinnest of the available weights which is called Thin. The typeface in question is Roboto.
I'm on Ubuntu 14.10. The truetype files are placed in:
/usr/share/fonts/truetype/roboto/
I have already copied this truetype directory including all files to:
~/.fonts
And:
~/.gimp-2.8/fonts/
I did sudo fc-cache -fv
as several times as well.
What could GIMP and Inkscape prevent from providing Roboto Thin?