Font Size is too small in Kubuntu 16.04 with a 4k display. How to enlarge the size of system fonts / symbols?

I have a 4k resolution screen and the display resolution shows: 3840x2160. I do not want to reduce this resolution. Here is the problem:

I see extremely small fonts, I need to touch my nose to the screen to see when:

1. I login for the first time after a fresh install of Kubuntu 16.04
2. Login screen after reboot or logoff
3. I install applications like Skype, Gedit, Matlab (img below)
4. grub loader screen
5. Small icons when looking through the system menu etc. (img below)

Solutions found:

1. Goto K button>System Settings>Font>Force Fonts DPI = 230
2. None yet
3. None Yet
4. Alter the resolution in /etc/default/grub
5. None Yet

Kindly help!

Screenshots:

Small fonts in apps

Small icons

System Specifications: Kubuntu 16.04, Dell Precision 5510 4k touch screen with NVIDIA Quadro M1000M

Solution 1:

Maybe this link helps: Is Ubuntu 4K ready?

This german article says that it was running without issues. The author describes that he was changing the scaling factor under the system preferences and that the scaling was set systemwide for all used fonts.

Kubuntu should probably also have a scaling factor in the settings but I don't know where.

Solution 2:

You can use Unity Tweak Tool in Ubuntu 16.04 LTS and 18.04 LTS. The settings I'm using for scaling on a 1920x1080 monitor are:

The Text scaling factor scales both fonts and UI elements like title bars, menus, etc.

Icon size is preset but the text size under it increases giving the illusion the icon size changed:

In the .gif above scaling starts at 1.38 on a 1920x1080 monitor. Then it is changed to 1 and everything gets tiny, which is normal. Then it is changed to 2 which is ideal for the visually challenged. Once again the icons have fixed pixel size and the font shrinking or expanding under the icon gives the illusion their size is changing.

To install Unity Tweak Tool use:

sudo apt install unity-tweak-tool

Others may be interested in the full suite of tools available in 18.04 LTS:

$ apt list | grep tweak
gajim-rostertweaks/bionic,bionic 1.0.0-3 all
gnome-tweak-tool/bionic,bionic 3.28.1-1 all
gnome-tweaks/bionic,bionic 3.28.1-1 all
mate-tweak/bionic,bionic 18.04.16-1 all
mousetweaks/bionic,bionic,now 3.12.0-4 amd64 [installed]
tweak/bionic 3.02-2 amd64
unity-tweak-tool/bionic,bionic,now 0.0.7ubuntu4 all [installed]