Wood has been humanity's basic building material throughout recorded history. It's versatile, easy to work with, and unlike money, it grows on trees. If the wood is painted, repairs are simple. Dents or other flaws can be filled with wood filler, and then painted over. Repairs to wood that's been stained, varnished, or otherwise finished to show the grain is as much an art as a skill. You want to repair the damage, but in a way that blends in with the original grain. For minor scratches, you can buy touch-up sticks that are a lot like crayons. Find one in a shade that matches the wood, and then rub the stick along the scratch. Repeat this procedure until the scratch disappears. More severe blemishes might require a shellac stick. If the surface is burned, scrape away until only bare wood shows. Mask off the area and use a hot knife or soldering iron to melt the shellac stick. It will drip down into the depression, filling the hole. When it's dry, carefully scrape it down to the level of the original surface and sand it smooth. You can use artists' acrylic paint and a fine brush to paint in the grain, if necessary. A layer of clear lacquer seals the surface. For dings in vertical surfaces like paneling, try one of the plastic-type wood fillers. You can try to find it in a shade that matches the original wood, or you can add a few drops of stain until it matches. Press it into the hole with a putty knife and wipe away any excess. When it dries, you can paint in the grain, if you want to.