If you are repainting a previously painted surface, it is important to know what was applied to the surface. If it is possible, bring a sample of the surface you are going to paint to your paint dealer, where they may be able to tell you what kind of paint that was used. If the surface was painted with distemper (e.g. Falu red distemper), just apply a new coat of distemper (after brushing off the surface). If you are painting a previously untreated surface, you are free to use whatever please you (i.e. alkyd paint, acrylate paint, distemper, wood stain, etc.).