I’m going to go out there and say it, I really like GNOME. I know that a lot of people don’t. Whatever. I’m usually on hardware fast enough that it can handle this beast of a DE. But, having just installed it on a ThinkPad X1 Carbon with a nice WQHD display, I was a little irritated that the only 2 display scale factors were 100% and 200%. Which is to say, “too tiny for most people without a microscope”, or “dangit now I can only see like 5 characters on the screen”. Basically, I needed 150% scale factor. This is how to get it.

The way to get this is slightly different for X and Wayland display servers, but generally pretty similar:

X:

$ gsettings set org.gnome.mutter experimental-features "['x11-randr-fractional-scaling']"

Wayland:

$ gsettings set org.gnome.mutter experimental-features "['scale-monitor-framebuffer']"

Credit goes to Ask Ubuntu