• Houses can include a variety of trim molding types.Photos.com/AbleStock.com/Getty Images
  
  Trim molding is added to the tops and bottoms of walls and around the edges of doors and windows to give normally flat surfaces more shape, definition and style. Traditionally made of wood, trim molding can also be made of plastic and includes several types. Included in types of trim molding are baseboards, crown molding, window and door casings and picture or chair rails. Each type of trim molding serves a different purpose and can have a variety of looks.
  
  

Crown Molding

• Crown molding can also be called ceiling or cornice molding. This trim molding is attached to the top of the wall where it meets the ceiling. Crown molding is crafted to have angles to fit the wall-ceiling crevice. Styles of crown molding can vary greatly from those with straight lines and minimal curves to those with intricate pattern designs carved into the molding.
  
  

Baseboards

• Baseboard is a type of trim that is placed on the bottom of the wall between the wall and floor. Baseboards can be narrow or as wide as 6 inches. They are typically designed to be thicker at the bottom near the floor and narrower at the top edge. While it can add decorative appeal to a home, a baseboard also serves as a protective barrier between the wall and vacuum cleaners, mops and other things that might cause dents or leave scuff marks. Baseboards can also hide any space between the lower edge of the wall and flooring.
  
  

Casings

• Casings are trim molding that is placed around windows and doors to make a frame for the opening. Casings can hide any space between the door or window and the wall. They are usually smaller but can be thicker than baseboards. Casings are often the most visible of trim moldings because they are closer to eye level, whereas crown molding and baseboards are placed much higher and lower than eye level. Casings are often also used around archways.
  
  

Rails

• Rail molding can be used for a chair rail or picture rail. A chair rail is a decorative accent that was originally designed to protect against possible damage caused by chairs bumping against the wall. Chair rails are also a way to divide two paint colors or one paint color from wallpaper. A chair rail is typically placed 3 feet from the floor while picture rails are positioned higher on walls. Picture rails include hooks for holding pictures so there is no need to place hooks into a wall when hanging art or photos. Both chair and picture rails run horizontally along the length of the wall.