Make the full version (7 weights + matching italics) open-source

[cssobral2013]

@bettergui - I found in your Behance these versions of Darker Grotesque: https://www.behance.net/gallery/74842505/Darker-Grotesque, go below and click 'Get Free Trials'
So, I'd like to you to make these open-source and replace this version.