Using a water-based primer to paint over wallpaper can cause the moisture to seep through and the wallpaper to bubble and peel, taking the new layer of paint with it. To avoid this problem you can prime the wallpaper with an oil-based paint. Imperfections from the wall paper will still show through the new paint but it won't cause any new damage. To reduce imperfections prepare the wallpapered wall by removing stray or curled pieces, sand lumps level and spackle holes.
Wall paneling isn't just the classic wood basement anymore. Paneling comes in a variety of colors and designs that can achieve effects that paint cannot. Wall paneling can add texture and depth to a room. The biggest advantage to using wall paneling to cover up wallpaper is that there is no moisture involved in the installation that may cause the wallpaper to peel of the wall.
Fabric adds texture to a room and can hide imperfections caused by old wallpaper. There are an infinite amount of color, texture and pattern combinations that can be used on walls. You can starch glue the fabric directly on the wallpaper, but to prevent peeling it's best to avoid using glue. If you have drywall you can use staples to secure the fabric to the walls. Using a staple gun, start at the top of the wall and staple the fabric along a straight line where the ceiling and wall meet. Stretch and pull the fabric flat while you staple a line along the other corners. Cover the staples with bias tape, cord, wood trim or any other kind of trim that matches the decor.
Depending on the wall space, you can use regular items to cover wallpaper. You can glue old CDs to add texture and shine to the wall. You can glue pennies, beads, bottle caps or vinyl record covers in different patterns and designs. You can also use different kind of materials like corkboard or foam paper that might be especially popular in a child's room. You can buy specialized paint that turns the walls into a chalkboard or a black magnetized wall.