System Three® makes a number of epoxy coatings which are extremely durable when cured, they do not need any additional protection when used indoors. When used outdoors though, they will weather in the sun and should be coated with a UV-inhibiting coating like our Spar Varnish or Pennant Topside Paint.
Decorative paints are easily applied over or under these coatings. If applied first, or underneath, they will need to be thoroughly dried or cured, and then sanded with no finer than 150-grit sandpaper to ensure good adhesion of the epoxy coating.
To apply decorative paint or artist colors over the epoxy, simply allow the resin to cure, then prepare the epoxy surface according to the paint manufacturer's directions.
As always, make sure to run a small test with the desired material prior to applying it to your entire project.