in any printing environment where liquid ink is applied to media by a swath printer the presently preferred embodiments of the invention are used in an inkjet printer of the type shown in fig1 in particular inkjet print 10 includes an input tray 12 containing sheets of media 14 which pass through a print zone and are slowly fed past an exit 18 into an output tray 16 referring to fig1 2 a movable carriage 20 holds print cartridges 22 24 26 and 28 which respectively hold yellow y magenta m cyan c and black k inks the front of the carriage has a support bumper 30 which rides along a guide 32 while the back of the carriage has multiple bushings such as 34 which ride along slide rod 36 the position of the carriage as it traverses back and forth across the media is determined from an encoder strip 38 in order to be sure that the various ink nozzles on each print cartridge are selectively fired at the appropriate time during a carriage scan each print cartridge has its own ink supply tube 40 42 44 46 for ink delivery from an off axis ink reservoir the unique features of the bellows diaphragm disclosed herein permits the construction of a differential pressure sensing and actuating diaphragm out of non ductile polyethylene aluminum composite foil without the necessity of joining any seams within the body of the foil when formed into bellows only the periphery of the formed bellows need be sealed to a mounting frame in this particular embodiment the foil which is utilized is presently qualified and used.