Paint and wallpaper can enhance any room, but there are a few things that must be done before applying either one to ensure proper adhesion or coverage. When applying wallpaper to a textured wall, the wall must be smoothed. You can smooth a wall by covering it with a ready-mix mud, or you by sanding it. Remember to cover any furniture in the room with plastic tarps or sheets. For wallpaper, you may choose to run a wall liner. This is applied with the same glue you will use for the wallpaper, but it is run along the wall horizontally. Regardless of texture, a smoothing method is not necessary if your walls were already painted with flat paint. Also, before applying the paint or wallpaper, cracks in your walls need to be filled, plaster patched, and dirt cleaned from the surface. After these steps are taken, a watered-down mix called a primer must be applied to make the wallpaper glue or paint adhere well. Next, apply your paper or paint. You still need to apply glue even if your paper is pre-pasted. Remember that paints usually dry a lighter shade than they appear in the can, but the hue will deepen in shade when it covers a larger surface area. For more information on preparing a room for paint or wallpaper, contact an expert in home improvement.