This gentleman's link was very helpful
Has a great answer:
Anyway, now you have your resolution set to whatever you need it to be. You’ll need to copy the settings file, which is located at
That file contains your display settings. In order to proceed further, you’re going to need access to root. I’m going to assume that you’ll achieve this access with
sudo. Open up a new terminal and enter the following:
sudo cp .config/monitors.xml /var/lib/gdm/.config/
sudo mkdir /etc/skel/.config
sudo cp .config/monitors.xml /etc/skel/.config/
The first line copies it over to GDM’s configuration so that GDM will display at the correct resolution. The second line creates a .config directory in your
/etc/skel, and then on the third line we make another copy of your
monitors.xml file into the
/etc/skel/.config so that when you create new accounts, they will automatically be set up with the monitors config, thus making a seamless transition for everyone.
You should also copy that file into any existing users if they aren’t properly configured already. Never again will you have to worry about a low resolution on your high resolution display.