Multiple sets, particularly endless sets

A multiple set comprising outer sheets and a plurality of intermediate sheets disposed between said outer sheets, said sheets being arranged in superimposed array, said intermediate sheets and at least one (11) of said outer sheets having at least one first communicating recess, said first communicating recess terminating at but not passing through said other outer sheet (14), first adhesive means (5c) disposed in said first communicating recess and contacting the other outer sheet (14), at least one second communicating recess in said one outer sheet (11) and in at least one first intermediate sheet (12), a second communicating recess terminating at but not passing through a second intermediate sheet (13) which is disposed further from said one outer sheet (11) than said first intermediate sheet (12), second adhesive means (5b) disposed in said second communicating recess and contacting said second intermediate sheet (13) along with said first intermediate sheet (12) disposed between said one outer sheet (11) and said second intermediate sheet (13), said first and second adhesive means (5c,5b) being applied by a single adhesive applying operation as the applied adhesive means passes through said first and second communicating recesses.