This should work on most Ubuntu based systems. This will give you a Gimp 2.10.30 (as of this writing) with some better brushes and a bunch of great plug-ins and helper scripts.
First things first. Open the terminal and issue the following two commands:
sudo apt update
sudo apt install gimp gimp-plugin-registry gmic
Once Gimp is installed open Gimp once and close. This will create the config section in your profile where you can place other brushes, plug-ins, and scripts you want to add yourself. We will use it to add the Gimp Shop Paint project brushes. This was a fork of Gimp to make it more like painter. I don’t think it’s still active but the brushes are nice.
Flatpak Version With Resynthesizer
If you want Resynthesizer healing functionaility, similar to Adobe’s Content Aware, grab the flatpak version of Gimp 2.10. It can be installed from the Pop! shop by selecting the flastpak in the drop down, you can install from the Gimp site, or using the command below. These plugins will not work with the Gimp 2.99 beta. The only beta plugin at this time is GMic.
Open the terminal and run: flatpak install –user org.gimp.GIMP.Plugin
Select the first option.
Select the plugins you want to install. If you are running Gnome 42 be sure to select plugins labeled 2-40. Pop! OS 22.04 is running 42. Unfortunetatly they need to be installed one at a time.
In the Gimp settings you can add plugin folder path where apt installs the other plugins, like the foundry scripts found in gimp-plugin-registry. You can also manually copy plugins and scripts in the folder in your profile ~/.config/GIMP/2.10 and make sure there are pointers in settings for those locations. Do this for brushes if not pointing to the .config path if you copy the brushes there.
Download GSP brushes from https://github.com/draekko-rand/gps-gimp-paint-studio/releases/download/GPS-v2.0/GPS_2_0.tar.gz
Unzip the contents and merge the contents into: ~/.config/GIMP/2.10
For more scripts and brushes see: https://www.gimphelp.org/script210.html
Install MyPaint, which will give you access to those brushes within Gimp also.
There are tons of people offering great brushes on Deviant Art. You will need to create an account to download them.
Time to paint!