DUPLI-COLOR Magnetic Paint is a water-based paint for indoor applications. The paint contains iron pigments, which allow to affix magnets on the painting.
The product offers a lot of applications in the most different fields in kindergarden, school, office, kids' rooms, etc.
As far as the paint has been applied in sufficiently thick coats, you can even re-coat it with any dispersion paint or repaper with a thin wallpaper - the magnetic properties will remain.
Overspraying with DUPLI-COLOR spray paints is also possible.