Abstract: An apparatus for spreading jointing adhesive on each side of a crosswise tear-off perforation on a paper web which makes one side of form envelopes, said apparatus comprising an adhesive spreading roll (2, 2") and a counter roll (6) for passing therebetween said paper web (7) with crosswise tear-off perforations. The periphery of adhesive spreading roll (2) is provided with two parallel arrays of adhesive nozzles (2a) extending longitudinally of the roll. In order to adapt the apparatus to forms of various sizes (to perforation gaps of various lengths), the distance of nozzle arrays (2a) from the center axis of rotation (3) of gluing roll (2) is adapted to be varied either in a manner that there are used several replaceable adhesive spreading rolls (2) having different diameters or in a manner that several nozzle rails (2b, 2c) having different heights can be replaced and fitted in a groove (2d) provided on roll (2').