CAUSES: Failures usually are the result of using the wrong type of poor quality roller cover or brush. Poor painting techniques. Repainting or touching-up partially dried areas add brush/roller marks. Painting non-primed surfaces with varying porosity.
SOLUTIONS: Proper surface preparation and application with the recommended quality roller cover or brush. Roller nap length should confirm to the paint type being used. High quality brushes will minimize brushmarks. Select a paint with good flow/levelling characteristics.