Painting question

Finished with my first shape (5’9" x 20 1.8" twin fish) and an artist friend of mine is jonesing to art up the bottom. Question is whether to have him paint on the foam or over the lam. Can detailed work even be done on the foam? My blank was a Clark super green, so other than avoiding solvent based paints anything else he should be aware of?

Howzit kim_dude, Have your friend do the basic paint job on the foam then finish the detail on the sanded hot coat. Aloha,Kokua