Abstract: This relates to the production of folders such as those commonly used for binding loose sheets of paper into booklet form. There is provided a method and an apparatus for setting fastener elements, such as tangs and eyelets, into selected portions of a blank made of heavy paper or cardboard. The apparatus employs rotary die holding elements defining a nip or nips therebetween for receiving one or more portions of a paper blank, particularly a blank folded to a T-shaped configuration. The apparatus includes means for applying setting forces to the fastener elements during the very brief interval of time that the fastener elements are disposed in the nip or nips between the die holders. Radially movable dies are mounted in certain of the rotary holders and cam means are employed to apply momentary fastener element setting forces to the fasteners.