A film assemblage for use with a camera of the self-developing type having a pair of pressure-applying assemblies, e.g., a pair of juxtaposed roller assemblies, for rupturing a container of processing liquid attached to a leading end of an exposed film unit and spreading its contents in a layer between elements of the film unit as it is being advanced between and in engagement with adjacent liquid spreading surfaces of the assemblies so as to initiate the formation of a visible image in the film unit. The film assemblage includes means for pregapping the adjacent liquid spreading surfaces to a degree which will in turn provide a processing liquid layer of an optimum thickness for the film units in that particular film assemblage.