I'm busy making a scale-model solar system, for teaching primary school children. Mercury, Venus, Earth and Mars are marbles, Jupiter and Saturn are kids' footballs, and Neptune and Uranus are tennis balls. At first I planned to shave the tennis balls before painted them, but then I wondered whether it was really necessary.
I changed my mind.
Then I went down the local art shop to buy paint, since it's not something I've needed for ages. I explained to the salesman what I wanted, and he didn't snigger. So now I've got the right sort of paint to use on sanded down plastic footballs. Watch this space.