Wallpaper is a material that is used to decorate and cover walls for the purpose of interior decoration. Wallpaper is generally sold by the roll, with various types of available includes non-waven wallpaper, paper wallpaper, photos wallpaper and metal wallpaper. In terms of size, the two most common trimmed rolled good sizes are sold in American and European. American rolled goods are 27 inches by 27 feet (8.2 m) in length and European rolled goods are 21.5 inches wide by 33 feet (10 m) in length. Wallpaper is commonly used to decorate walls in various buildings including offices, homes, museums, cafes, restaurants, and shops.