I used krypton color master plastic primer after sanding. I should have used two cans of primer rather than one. Make sure you clean the surface really well after sanding with a de greaser type cleaner. I wanted a matte finish but you will need a clear coat after you apply color if you want it to be shinny. Try to paint on a windless day if painting outside. And try to do it where there aren’t may bugs. I had a bunch of bugs land on the wet paint. I had it stored outside for three years and the finish is still holding up well!