An interfolder separator apparatus and method utilize a pair of count fingers that are movable longitudinally along and transversely to a stream of folded sheets, for temporarily supporting each successive pack formed by the separator and then releasing each successive pack when partly completed to alternating build fingers, so that the operation of separating successive packs from one another is performed separately from the operations of completing the build of each pack and transporting the completed packs to downstream operations. The count fingers may be mounted to pivot about axes that are movable longitudinally along and transversely to the stream of sheets. A first or last panel of the completed pack may also be folded back partly upon itself, after the partly completed pack is released by the count fingers. Some or all of the fingers may be spring loaded and automatically resettable for clearing jams.