This past weekend I went to a panel and she said that PlastiDip works amazingly on craft foam. You just need to make sure to be close to whatever your spraying to get a smooth surface, and wear a mask!
Next Up: Ohayocon 2015
Hazel Tellington, Gaz Membrane, Kyo Sohma (tomboy)
2015 Plans: Ohayocon, MARcon, Origins (maybe), DragonCon