Wallpaper 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 rollsand are put onto a wall using wallpaper paste. Wallpapers can come either plain (so thatit can be painted), or with patterned graphics.
Wallpaper printing techniques include surface printing, silk screen-printing, and rotaryprinting. Mathematically speaking, there are seventeen basic patterns, described aswallpaper groups, that can be used to tile an infinite plane. All manufactured wallpaperpatterns are based on these groups. A single pattern can be issued in several differentcolorways.