outer surface of the working blade the third is the contact line 21 between the wear bar 8 closest to the yankee surface and the inner surface of the working blade and the fourth is the contact force 22 between the base of the cartridge and the bottom edge of the blade preferably the doctor blade support structure is an aluminum extrusion however it could also be a fiber reinforced plastic composite material pultruded or laid up to obtain the correct geometry or may be an assembly of metallic components the profiling plate 4 extends in the longitudinal direction and is attached along the bottom edge thereof to the holder mounting plate 13 with spherical type mounting arrangements 23 a series of mutually spaced pins 49 adjustment mechanisms 29 are provided along the longitudinal direction of the profiling plate 4 and the holder mounting plate 13 that permit the profiling plate 4 to be moved a small amount away from the holder mounting plate 13 in order to accommodate small variations in the distance between the tip of the doctor blade 2 and the roll surface 1 this is shown in more detail in fig5 which shows the holder in cross section with the profiling plate adjusted towards the yankee for example and as discussed above certain yankee doctor rolls may have diameters at the ends of the roll that are smaller than the diameter at the center of the roll e g be barrel shaped in this case the adjustment mechanisms 29 provide that the blade may be pushed toward the roll surface at the ends to match the shape of.