A center justified pin registration system uses a plurality of pairs of registration pins having different thickness heads to align an edge of a printing plate when mounting the plate to a drum of an imaging system. The registration pins are optionally adjustable. The registration system avoids the requirement to punch holes or notches in a printing plate and does not require adjusting the thickness of a common registration pin. The registration system allows printing plates having different widths to be mounted without necessitating adjustments of the registration pins. An alternate embodiment employs a plurality of pairs of registration pins having uniform thickness heads.