I used a whole sheet of Arches cold press 300lb watercolour paper for this interpretation of the solar system. I used reference photos from the NASA website which are public domain. It is such a large painting and I have such limited space that eventually I abandoned it but I guess it is done enough that I could call it finished. Or maybe I'll tweak it one day.
The painting in the early stages...
The paint used was Schmincke Horadam from my self-customised box set...