The ArtRage painting files (*.ptg) contain a lot of information ArtRage needs to make the paints act naturally. As a result, they can be quite huge and would soak up all our server space.
In the ArtRage File menu, you can export your image as a jpg which is a lot smaller (but not as good quality) for posting to the forums here.
Note that it is important you also keep a copy of your work as an ArtRage painting file so you can go back and continue working with it at the same quality it was when you started it.
AndyRage's mantra for graphics engine code:
"Sure - how hard can it be?"