The package will be updated on a weekly basis, like the v2.10.x one.
I am now in the process of checking which plugins are compatible with the GTK3 version , and eventually help updating those that have incompatibilities.
Please report any issue you might encounter, preferentially using the GitHub issues tracker.
I couldn’t find a way to change the icon size, the default size it a bit large. The option in the GTK3 build is not where it exists in the GTK2 one.
Apparently I cannot run GIMP-2.10.8 which is installed normally on my system at the same time as this AppImage. I tried running one first and then the other, and vice-versa, but neither combination resulted in two concurrent GIMP instances running.
Though this probably has nothing to do with the AppImage, I’ll comment that the GTK2 theme is far easier on the eyes due to lower contrast icons, and it correctly has neutral colors while the GTK3 theme has non-neutral colors which should not be the case in an image editing program.
This does not exist anymore because this was only a trick to get bigger icons on high density displays automatically (i.e. pixel density detection) in GTK+2. In GIMP 3, we are back at how it should be, i.e. that:
Choosing the size of icons is back as a theme settings only, as it should be. When GIMP 3 will be out, I expect people to just release themes with smaller icons, or themes with bigger icons. Maybe we will also just add back a “Small” theme (as we used to have in 2.8). We’ll see.
By the way, themes in GTK+3 are CSS-like, which should make them much more easily customizable by more people than it uses to.
Pixel density detection follows the desktop settings. So if your desktop is set to 2x scale, GIMP follows and the theme icon size is simply doubled. No trick overriding the theme.
I’ll comment that the GTK2 theme is far easier on the eyes due to lower contrast icons
Once again, this is a theme thing. Currently in the dev branch, we only have a “System” theme, which basically means it uses whatever is your GTK+ default theme. Symbolic icons in particular are simply recolored with whatever is your theme’s foreground and background colors. If the colors are bad, it means you chose a system theme with such colors.
Note that we may add again themes to override most basic settings (in particular color settings). I’m pretty sure we have a bug report about this (and in particular for this neutral color issue in many of GTK+ third-party themes) actually. I also expect once again that third-party themes will be released by people (and since I am working on an extension management system, they should be easily findable and installable).