[1] http://www.omgubuntu.co.uk/2017/09/enable-fractional-scaling...
For users of older Gnome versions, note that you can change both the font scaling (text-scaling-factor) and global UI scaling factors.
If you, like me, have a screen that needs 1.5 scale, you can either set UI scale to 1 and font scale to 1.5, or UI scale to 2 and font scale to 0.5.
That's almost as good as real fractional UI scaling.
Fractional scaling on 3.28 will allow you to have different scaling for each display. Will also be more consistent across different apps (Gtk, Qt, electron, etc.).
Numix window decorations scale (where Arc doesn't) - I use Numix anyway so it works out, can't wait for proper fractional scaling since I'm a cinnamon user we'l likely get it around the same time.
$ cat .Xresources
Xft.dpi: 144
Xft.hinting: 1
Xft.hintstyle: hintslight
Xft.antialias: 1
Xft.rgba: none
Xcursor.size: 48
Xcursor.theme: AdwaitaIt does work with X11 for me.
Looking forward to the new display settings in Gnome 3.26 https://help.gnome.org/misc/release-notes/3.26/