Ceramic tile backsplashes are made of some of the smoothest building materials available. However, the adhesive holding the tile in place is not as strong as you may think it is. You could use a very strong adhesive to put paneling, other tile or wallpaper over your existing tile backsplash, but over time, the added weight of the second layer of material will start pulling on the tile. Moisture will also get trapped in behind the new material, causing the adhesive on the ceramic tile to become loose. While you theoretically could put something over your ceramic tile backsplash, the best approach is to remove the tile first and then put your new backsplash up.