an air cushion guide for sheet or web - formed material that includes at least one guide member having a chamber and a surface formed with nozzle openings that may communicate with the chamber , through which air is blown between the guide member and the guided material for supporting the guided material on a supporting air cushion located above the guide member . each of the nozzle openings has a cross sectional area . at least one moveable element is constructed to vary a volumetric flow of air emitted from the nozzle openings to form the air cushion guide . the moveable element is selected from the group consisting of a component having a movement which changes a number of the nozzle openings formed in the surface that are supplied with blown air , and at least one component having a movement that changes the cross sectional area of at least one of the nozzle openings formed in the surface . a control unit is provided for controlling a movement of the at least one moveable element .