* Load up your roller with lots of paint. Painting with too little paint on a roller, known as “dry napping,” results in tiny gaps in the paint-it’s among the most common mistakes DIYer painters make. A too-dry roller even could pick up paint already applied rather than lay additional paint down.
Not sure if you have enough paint on the roller? Listen. A dry roller makes a hissing sound as it rolls along the surface…a roller with sufficient paint sounds moist. (Once you hear both of these sounds the difference should be clear.)
Tip: Some amateurs use too little paint on their rollers because they want to avoid the drips and splatter that can occur when a roller heavily loaded with paint is lifted to the wall or ceiling. These drips can be minimized by rotating the handle of the roller 180 degrees once or twice to reverse the drippy paint as you lift it toward the surface to be painted.