There are two basic types of exterior paint: water-based latex and oil-based alkyd. Latex cleans up with soap and water, dries quickly, has low odor, and remains flexible longer so it’s less likely to crack. The best quality latex paints contain 100 percent acrylic resins.
Alkyd paints require mineral spirits (paint thinner) for cleanup as opposed to just soap and water. But many professional painters prefer alkyd paint because it’s durable, stain-resistant, flows very smoothly, and dries with fewer brush marks. But alkyds have a strong solvent smell and dry very slowly.
The one you choose is up to you. Just remember that if you’re applying latex paint over an existing alkyd paint, you must first prime the surface to ensure the new topcoat will adhere to the old oil-based paint.
