Abstract: In order to wrap individual slide-fastener units in plastic display envelopes enabling the testing of their sliders without removal from the package, a continuous strip of preferably transparent thermoplastic sheet material is advanced together with an integral series of such units past a cutting station where the units are separated from one another with simultaneous severance of the plastic strip. The latter, on approaching the cutting station, is folded from opposite sides around the outer edges of the carrier bands supporting the interlinked coupling elements of the units, the resulting flaps being kept spaced apart by a median gap exposing the juxtaposed coupling elements as well as the associated slider. The flaps are fastened with light adhesive bonding to opposite ends of the stringer tapes cut from the carrier bands.