Lay a drop cloth down around the edges of the wall you are going to paint, which will protect your flooring from accidental paint spills.
Apply 3-inch-wide paint tape surrounding the area you will be applying glossy paint. Paint tape can be applied and removed without peeling off existing wall paint and without leaving behind sticky residue.
Smooth down the paint tape to remove any bubbles or buckling.
Fill a paint tray with clear, glossy latex paint, and coat a paint roller in the glossy paint.
Roll the coated paint roller over the patch of the wall that you blocked out with paint tape. Cover the area with an even layer, then allow the paint to dry for two hours.
Apply a second layer of glossy paint as before, and allow the paint to dry for two more hours.
Remove the paint tape to reveal the completed glossy wall patch. Repeat to add on as many glossy wall patches as you like.