How to Load a Roller Cover
Many painters “break in” a roller cover by priming it with water or thinner. In our lab we never prewet a cover before painting. If you choose to, you must spin it out with five or six strong pumps so it is only lightly damp. Then take even more moisture out by blotting the cover with a paper towel. Wooster recommends conditioning only for water-based paints, using water.
Use a liner in the paint tray to save time during cleanup. Thoroughly mix the paint, then pour some in the well of the tray. Don’t overfill—the well should be half empty. You need room to roll excess paint onto the tray’s roll-off area.
With the roller cover on the frame, drag some paint with the edge of the cover from the tray well back onto the roll-off area. Do not submerge the cover. Roll it on the grid toward the well using several quick forward strokes, then drag more paint back with the cover. Continue until it is completely saturated but not dripping.
Patience is very important when loading a cover. It takes time to work paint through the fabric down to the core, especially with woven fabrics. Allow several minutes for the initial loading.
Do not “starve the cover” by attempting to paint too far without refilling—that can compress the fibers and make it more difficult to reload, forcing you to spend more time in the tray.