Once the surface has been prepared by pressure washing, cracks and bulges have been repaired, you are ready to begin the application process.
There are numerous coatings that can be used to paint stucco. A high-quality flat latex paint such as Sherwin Williams Super Paint is a good coating and has good longevity.
The next level up is to apply an elastomeric such as Sherwin Williams Sherlastic. This is a thicker coating that gives you protection and has the ability to stretch and to be very elastic. It also fills small spider vein cracks when rolled.
The best coating would be Sherwin Williams Loxon XP. This product is a paint that is thick and acts like an elastomeric, and offers the additional protection from wind driven rain and water intrusion. It also has the ability to fill spider vein cracks when rolled.
There is an additional advantage of Sherwin Williams Sherlastic and Sherwin Williams Loxon XP. These coatings are so flexible, small spider vein cracks that may develop in the future are safely bridged over and do not break thru the thick elastic coating.
The method of application has a great deal to do with longevity. A coating can be just sprayed on and it will look good and have good performance. A better application process for increased longevity would be to spray and while the coating is still wet to “back roll” through it. This “back rolling” forces the material into the pores of the stucco surface. If the surface is just sprayed there will be pin holing. (If you were to spray pieces of glass and let it dry you would see that there are tiny pin holes throughout the sprayed coating). These pin holes are tiny weak places in the paint coating. As the house weathers, mildew can grow on the original surface through these tiny holes. The process of spraying and back rolling eliminates pin holing and also results in a thicker coating.
If greater longevity is desired, you can spray and back roll the first coat and then while the coating is still wet apply another medium spray coat on top of the wet back rolled surface.
The longest lasting process would be to coat the stucco with a first coat that is sprayed, and back rolled, let it dry for 24 hours. Then apply a final sprayed finish coat to the surface.