On my dell XPS 13, 9360 model, there is a HiDPI display, the resolution is 3200x1800 which is fantastic but it has resulted in some GTK applications (and multiple Qt applications) not having the correct scaling factor applied. I have already fixed this for Qt applications but now I would like to fix it for GTK-based applications like the GIMP and other programs.
Here is an example of what I mean:
The whole user interface of the GIMP is at 1x (unscaled) while the file manager is at 1.5x or 2x; it's the perfect scaled size.
How do I fix this? With a tweak tool or use gconf editor or something else?