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Claim 1

A BLANK FOR A FOLDED DOCUMENT OR FILE BOX OF PREDETERMINED SIZE AND VARIABLE THICKNESS COMPRISING A PIECE OF SHEET MATERIAL HAVING A CENTRAL RECTANGULAR AREA OF A STANDARDIZED SIZE FOR PROVIDING A SIDE WALL OF THE BOX AND HAVING AT ITS EDGES FLAPS FOLDABLE ALONG SAID EDGES TO PROVIDE EDGE WALLS OF SAID BOX, EACH OF SAID EDGE FLAPS BEING PROVIDED WITH A SERIES OF UNIFORMLY SPACED PARALLEL SCORE LINES LOCATED AT THE SAME DISTANCES FROM THE RESPECTIVE EDGE OF SAID CENTRAL AREA, TWO ADJACENT FLAPS HAVING EACH AN ADDITIONAL LENGTH FOLDABLE ALONG ANY OF THE SCORE LINES OF SAID SERIES OF SCORE LINES TO OVERLAP EACH OTHER, A LOCKING TONGUE IN THE ADDITIONAL LENGTH OF ONE OF SAID FLAPS AND A SERIES OF PARALLEL DIAGONALLY SPACED SLOTS IN THE OTHER OF SAID FLAPS, SAID SLOTS BEING SPACED IN CONFORMITY WITH THE SPACING OF SAID SCORE LINES, AND ONE OF THE REMAINING FLAPS HAVING AN ADDITIONAL LENGTH LONG ENOUGH TO EXTEND OVER THE SIDE SURFACE OF THE BOX OPPOSITE TO THAT FORMED BY SAID CENTRAL AREA AS WELL AS OVER THE OPPOSITE EDGE WALL AND THE OUTER SURFACE OF THE SIDE WALL FORMED OF SAID CENTRAL AREA WITH WHICH IT ENGAGES, SAID ADDITIONAL LENGTH HAVING IN THE REGIONS OF THE RESPECTIVE CORNERS OVER WHICH IT IS BENT A SERIES OF PARALLEL SCORE LINES OF THE SAME SPACING AS SAID PREVIOUSLY MENTIONED SERIES OF SCORE LINES.