A membrane keyboard, in the narrower or classic sense, is a keyboard made only of (plastic) foils. The necessary circuits are printed with conductive silver paste on one or more layers of foil and the button itself can be designed with or without a metallic snap disk. This design is particularly suitable for membrane keyboards with increased demands on durability, dust and water tightness or if a high level of media resistance is generally required. In a broader sense, membrane keyboards are characterized by a closed membrane surface. The underlying functional levels or components can, but need not, be based on plastic films. One advantage here is the great freedom of design: lighting, pushbuttons, short-stroke buttons, capacitive circuit board-based or printed conductive silver, touchscreens and much more can be integrated without giving up the closed surface.