I have tried to look for myself but have not found the information I'm looking for.
I've seen that one can use the digital painting software Krita in connection with Blender. But I do not remember how to do so. Is this possible?
The site lists the features as:
One-sided modes. Hit a shortcut in your image editor to make the texture update in Blender. Hit a shortcut in Blender to make the
texture update in your image editor.
Two-sided mode. Work in your image editor while the texture updates by itself in Blender, or switch to working in Blender while the
texture updates by itself in your image editor. The updates happen
only when you are actively tweaking the image, and at a frequency
that you set.
You could set the path to Krita or any other external image procesing application in Blender's User Preferences accessible from the file menu.
From the image editor you can launch Krita with the image loaded by chosing Edit Externally. When returned to Blender refresh the image with Reload Image or Alt-R.