Sand the surface of the wall using an electric sander with a medium-grit sanding belt to remove the folds and creases of the wrinkled texture.
Sand the surface again using the electric sander with a fine-grit sanding belt to smooth and buff the surface of the wall.
Wipe off the wall using a damp washcloth, then vacuum the surrounding areas to remove any debris. Allow the wall to dry for four hours.
Fill a paint tray with matte latex wall paint, then coat a 2-inch flat paintbrush with the paint. Apply the paint over the top and bottom edge of the wall.
Coat a paint roller in the matte latex wall paint, then apply the paint over the entire surface of the flattened wall. Allow the matte paint to dry for eight to 12 hours.
Apply a second layer of latex wall paint using the same method as before, then allow the second coat of paint to dry for an additional eight to 12 hours.