stabilizer 10 is provided with an inlet venturi 16 a main venturi 17 and an outlet venturi 18 the detailed internal structure of the sheet stabilizer 10 of fig2 is shown in fig3 as shown in fig3 the inlet venturi 16 is formed by the surface 20 and surfaces 21 22 which are substantially parallel thereto primary air from one nozzle 23 or from a series of nozzles is discharged into the throat 24 which is formed by surfaces 20 and 21 22 the suction thus created draws air in through opening 25 as shown by arrows a the combined air is discharged through inlet discharge opening 26 air which is carried along by the felt or the like 11 is exhausted through the outlet venturi 17 the outlet venturi 17 is formed by the surface 30 and surfaces 31 32 substantially parallel thereto primary air from one nozzle 33 or from a series of nozzles is discharged into the throat 34 which is formed by surfaces 30 and 31 32 the suction thus created draws air in through opening 35 as shown by arrow b the combined air is discharged through outlet discharge opening 36 the main function of the sheet stabilizer 10 is to create a negative pressure above the felt or the like 11 so as to keep the sheet 15 in close contact with the felt or the like 11 this is primarily achieved by the main venturi 18 air is exhausted from.