I use high quality art materials and follow the manufacturer's directions for use.
Walls are as uniquely individual as people.
If one could use a stop-action camera to record the activity of the type of outdoor walls typically used for mural painting, we would see an amazing variety of ways in which they breathe, peel, swell, sweat, shudder, and exfoliate particles. Since such dramatic activity is occurring to these walls day and night, rain and shine, we should not be surprised that the murals painted on them are inevitably affected. Historically, wall selection and preparation has played a major role in the creation of the greatest mural masterpieces. Mosaics require specific engineering calculation to interface successfully with most murals. Today, acrylic polymer murals on exterior masonry walls have arisen as a popular form of production, but little thought has been given until recently to preparatory work prior to painting or to preservability once completed.