Sand the Venetian wall in a circular pattern until the surface is dull and any sheen is gone. The wall will be slightly rough to the touch.
Vacuum up any dust from wall with the brush attachment. Vacuum the wall as well as the floor.
Set a drop cloth below the wall to prevent drips of paint from getting on your floor.
Apply the primer to the Venetian wall with a paint roller. Allow the primer to dry for at least 24 hours.
Paint the Venetian wall with the plaster paint. Use the paint roller to paint the wall in 4-foot squares. Paint over to the adjacent squares before the square you’re painting dries to avoid paint lines.