Abstract: A printer has first and second print mechanisms separated by a gap for the passage of a print medium. The print mechanisms are mounted on relatively movable support members. A gap adjustment mechanisms has one set of cam means for moving the support members relative to each other for both forms loading and forms thickness adjusting. The cam means comprises a pair of elongate cam bars translatable along one support member and follower pins on the other member which are located in camming slots formed in the cam bars. The camming slots have first and second camming sections in the form of linear ramps with gentle and steep slope angles respectively. The cam bars are translatable by pinion gearing in engagement with rack gearing on the cam bars, the pinion gears being on a shaft rotatable by a knob to thereby cause the follower pins to be cammed by either the first linear ramp for forms thickness adjustment or the second linear ramp for forms loading.