Abstract: A stubless unit set of multiple plies of the type including at least superimposed top, intermediate and bottom plies is made by removably interconnecting the top and bottom plies together and by removably interconnecting the intermediate and bottom plies together. The top and bottom plies are interconnected by providing a fold flap along an edge of the top ply, applying detachable adhesive to the flap, folding the flap to underlie the bottom ply and contacting the bottom ply with the adhesive, and the intermediate and bottom plies are interconnected by providing at least one hole in the bottom ply and extending a portion of the adhesive through the hole so as to contact the intermediate ply. Each of the plies is devoid of any tear lines which may form a stub.

Abstract: A unit set or assembly of several superimposed parts form a mailer without a stub, folded and detachable glue flaps on the top part underlying and being secured to the bottom part. A three-part mailer construction is formed wherein the intermediate part is secured to the bottom part as the adhesive on one of the flaps extends through holes provided in the bottom part. Removal of the top part therefore leaves the intermediate and bottom parts intact, or removal of the intermediate part leaves the top and bottom parts interconnected, or removal of the top and intermediate parts separates each of the parts from one another.A minimum four-part mailer construction is also provided of superimposed parts with the first part having the folded and detachable glue flaps underlying and secured to the fourth part.

Abstract: A unit set or assembly of multiple plies includes superimposed top, intermediate and bottom plies as well as a cover ply disposed over the top ply. A flap is removably connected to this cover ply along the line of weakening and underlies the bottom ply. First and second axially aligned holes of different sizes are respectively provided in the bottom and intermediate plies, the size of the bottom ply holes being less than the size of the intermediate ply holes. Adhesive is provided on the flap for securing the top ply thereto, such adhesive extending through the intermediate ply holes. The size difference between the axially aligned holes defines portions of the bottom ply which serve to mask the intermediate ply holes so as to confine the cross-sectional size of the adhesive, which extends therethrough, to the smaller size of the bottom ply holes.

Abstract: A rotary die cutter comprises a pair of plate and anvil cylinders rotatable about fixed and spaced axes for die cutting a web passing therebetween. A die cutting plate is secured along the periphery of the plate cylinder, and an anvil plate is secured along the periphery of the anvil cylinder. The clearance between plate and anvil cylinders is determined by the thickness of the anvil plate thereby providing an interference between plates for a clear-through die cut or a gap for die cutting less than each layer of a multi-layered material depending on the thickness of the anvil plate selected.