evacuated and pressure is applied to the rear highly flexible pu film whereby the originally separated u03bb 4 layers are changed to a u03bb 2 condition of minimal reflection as a supplement to the first second and third embodiments the pressure may also be generated hydrostatically by feeding a liquid on the one hand in this case for example chamber ii is filled with a highly transparent liquid chamber iii simultaneously remaining empty fig4 2 this represents the transmissive condition of the overall system as an alternative the transparent liquid is removed from chamber ii and chamber iii is filled with an absorbing liquid as illustrated in fig4 3 here also a hydrostatic pressure is exercised on the interference cell i this configuration describes the absorptive condition of the overall system if instead of a transparent and an absorbing liquid two liquids with different colors or different degrees of absorption are selected by means of this system in addition to a reflective condition two conditions of different colorings or absorptions may also be represented a preferred application of panes which can be switched between being transmissive and reflective is its use in a motor vehicle in this case panes of.