Artists are using foam core boards for fine art painting but the material is not archival quality. Foam core boards have a polystyrene, pillow-like centre which will eventually breakdown from ultraviolet light. It can be damaged by dents or punctures and the paper facing cannot withstand moisture. Solvents --- including shellac --- and lacquers will also erode the polystyrene centres. Artists must keep in mind the material's properties if they wish to paint on foam core board.
Spray paint is paint contained inside an aerosol can. It sprays a mist of paint that creates a more uniform application than brushes. Foam core boards are sensitive to moisture and spray paint has less moisture than many other paints. It is also faster drying than oil paints applied by brush. Some of the solvents may damage the inner polystyrene in the foam board, so the spray paint should be used only on the paper exterior.
Acrylic paints were introduced into the marketplace in the 1950s. Acrylic was first used as house paint because it was fast drying and durable. Artists began using the paint because it dried much faster than oil paint, and it adhered to most surfaces. It has an even sheen and it does not need a base coat as oil paint requires. On foam board, acrylic paint is ideal because you do not need to use solvents as with oil paints.
Oil paints were made famous by the Renaissance painters, who used the medium to create luminous rich paintings. Oil paints are a mixture of dry pigments with an oil such as linseed. It is slow drying and it may slide off the foam core board's slick paper surface. The board should be placed flat for oil painting. Shellacs and solvents will damage the polystyrene foam sandwiched between the paper exterior, so artists who use oil paints should either not use varnish or paint thinner, or use them sparingly.
Gouache paint is a mixture of pigment with gum Arabic and is similar to watercolour paints. Watercolour paints should not be used on foam core board because the paper will be damaged by the moisture. Gouache can give similar results of watercolour paints without the excess wetness. Gouache is easier to control than watercolour and is versatile in its application and results. Commercial artists use this medium because it can create very detailed work and it does not need many layers.