Wallpaper in Hummelstown is a kind of material used to cover and decorate the interior walls of homes, offices, and other buildings; it is one aspect of interior decoration. It is usually sold in rolls in the city, and is put onto a wall using wallpaper paste. Wallpapers can come plain (so that it can be painted), textured, or with patterned graphics. Wallpaper printing techniques include surface printing, silk screen-printing, rotary printing and digital printing. There are seventeen basic patterns, described as wallpaper groups, which can be used to tile an infinite plain. All manufactured wallpaper patterns are based on these groups. A single pattern can be issued in several different ways.