Eggshell paint has become popular with both homeowners and decorators. Its finish isn't as flat as regular flat paint, but it doesn't have the sheen of gloss enamel. Eggshell paint can be applied on any surface, the only difference between surfaces is the preparation you may need before applying the paint. High gloss enamel is a very slick surface, that is usually used in bathrooms or kitchens. If you want to put eggshell over it, you should first put one or two coats of primer on the walls, to give the eggshell paint a surface to "bite" into and hold.