Small 1/4″ nap roller covers or foam rollers will produce the smoothest finish and are ideal for use on walls, wood, and metal surfaces. It's important to choose the right size nap for your project. If you use a thick 3/4″ nap roller cover on a smooth wall, it will produce an orange peel textured surface.
Then, what uses more paint roller or spray?
In general, you will use up to three times more paint by spraying than by brushing–plus, you risk getting a thinner coat. Spraying uses more paint because the sprayer atomizes the paint into tiny droplets. This is inherent with paint spraying, and little can be done to control it.
Can you use spray paint on a popcorn ceiling?
Don't roll back and forth because once the popcorn gets wet it starts to peel. For stains, roll or spray paint the stained spot, with the same color the ceiling will be painted with, and let dry completly before painting the entire ceiling.