Abstract: In a method of rendering subject matter which is printed on one surface of a computer paper sheet unintelligible, an alpha-numeric interference pattern is printed over substantially the entire printing area of the surface of the sheet carrying the printed subject matter, the density of the interference pattern being sufficient to render the printed subject matter unintelligible. One particular use of the method is in the overprinting of computer print-out paper having printed information on one surface, so that the paper may be reused by printing on its opposite surface without permitting access to the information on the first-printed surface. A machine is disclosed for this application of the method.

Abstract: A device and method for interconnecting sections of fan-folded sheets to form a composite stack of a predetermined size. A base having an upper planer surface is provided for supporting a trailing transverse edge of the last sheet of a first section in abutting edge to edge relationship with the leading transverse edge of the first sheet of a succeeding section. Guide pins are located on the upper surface to assist in the positioning of the sheets. Splicing tape containing a centrally located row of longitudinally-extending perforations is then manually or automatically applied to regions of the sheets adjoining the abutting edges, with the perforations centrally located in a region between the abutting edges. One embodiment of the device of the present invention provides a mechanism for perforating the tape before it is applied to the adjoining edges.