What can use to paint foam?

[Kimbles20]

My boyfriend brought home a big square of foam recently and decided that he would like to make a tractor with it for his bosses son (we get on really well with the family and Jasper, the son thinks the world of my boyfriend and visa versa!)
Anyway, he cut out the shape with a craft knife but all we had to colour it was a ink pad used for inking stamps. He used this on the foam 4 days ago but it is still wet! Any ideas what he can paint over it with that will dry?

[bricro1]

A cement based paint should do the trick..(smooth)
Try and find someone with
"a bit left over."
I use it for all sorts of jobs.
Good luck

[bimbo123456]

You coould try emulsion. It is slightly plasticy.

[joko]

acrylic paint is the best thing.
the ink was a bad move

acrylic will seal the foam so that the ink will not go everywhere
the ink will not dry properly ever as foam is not porous like paper, and any wetness will make it go everywhere, all over the child and house.
children also may put it in their mouth, leave it in the rain etc
kind of irresponsible actually - health and safety and toxic substances etc
wash it out as much as possible.

acrylic is 'bendy' and won't flake and is waterproof.