A method is disclosed for forming reclosable packages at a form, fill and seal (FFS) apparatus by advancing a film of package making material longitudinally to form a tube while guiding opposite longitudinal edges of the film into a fin. A zipper having interlocking members and an attached flange is fed into the fin by capturing external surfaces of the interlocking members within a first guide member positioned adjacent to said fin and feeding the flanges along opposite sides of a second guide member positioned within said fin. An apparatus for performing the method is also disclosed.