Changing the Size of dockable dialogs and more

[HauntedGhost]

As no new answers have been added since 2021, hence, the OP has probably found the right answer. However, if anyone is still looking for a solution, then I just found an extremely easy solution to update GIMP’s these by manually editing GIMP’s theme file. You need to edit the gtkrc theme file and make appropriate changes to change the text of the GIMP’s interface.

Here are the steps:

Change font size

Close Gimp
Open the file gtkrc of your specific theme in a text editor
Open the Gimp themes directory:
Mac: /Applications/GIMP-2.10.app/Contents/Resources/share/gimp/2.0/themes/
Windows: C:\Program Files\GIMP 2\share\gimp\2.0\themes\
Ubuntu: /usr/share/gimp/2.0/themes/
Open the gtkrc file for your theme:
Light: Light/gtkrc
Dark: Dark/gtkrc
Gray: Gray/gtkrc
System System/gtkrc
other
If you have a customized Gimp, look here for the gtkrc file
Mac: ~/Library/Application Support/GIMP/2.10/themes
Find line with: GimpDock::font-scale = 0.8333
Replace with: GimpDock::font-scale = 1.35 (or another value) [1.35 did the trick for me; you can play around with the value to find which one would suit your specific needs.]
Start Gimp again

I have taken this information from SuperUser.com; the original answer was posted by Charlotte. You can find the details here:

https://superuser.com/questions/1513000/...dpi-screen