in the form of a rounded rib which projects toward the roll 7 means for effecting tilting adjustments of the baffle 40 desirably comprises a simple elongate tubular bladder member 48 suitably mounted along and under the baffle 40 as close to the hinge 44 as practicable to attain maximum leverage advantage desirably the tubular member 48 has a base 49 which is complementally engaged in a dovetail groove 50 located in an inset upwardly facing ledge 51 a crown rib 52 on the inflatable member 48 projects toward and is engageable in upwardly thrusting relation against the baffle member 40 and is adapted by inflation of the tubular member to move from a reverted position as shown in dash outline to an extended baffle tilting position as shown in full outline by controlling the inflation of the member 48 the degree of tilting of the baffle 40 about the hinge 44 toward the overlying backing roll 7 is adjustable within extremely fine increments to attain the optimum width of the orifice 39 for just the right pond back pressure in the chamber 37 to attain the desired coating results in any adjusted relationship of the doctor blade 14 to the backing roll 7 and thereby the web w any suitable means may be provided for controlling inflation of the member 48 such for example as a duct 53 communicating with the chamber within the member 48 and deriving air pressure from a source 54 through a control valve 55 by which the degree of inflation of the member 48 is adjustable and adapted to be maintained during operation of.