PS Foam / Foam Board /Depron
as they usually called depending on which country. its the most versatile all around foam use in any crafting model, Our uses here mainly on RC aircraft, as they are really Popular in the RC community. whether its scale semi profile or profile aircraft design anything goes. they are the lightest among the foam great for building indoor micro models or light wing loading aircraft.
Paint: use waterbase paint like poster color or if spray can is to be use , dust spray it 2ft away from the foam