algent Thanks a lot! I tried a lot using
lightdm-gtk-greeter-settings but none of those worked. I was probably going wrong somewhere, but it was setting the login screen wallpaper back to the default Desktop Wallpaper (
/usr/share/backgrounds/solus) instead of the one I had set.
Pines.jpg wasn't even set as my Desktop Wallpaper.
Anyway, thanks a lot, once again.