Abstract: The present invention relates to a one-piece blank (14) made of corrugated cardboard for the production of a display case (1), the case, the method and the machine for producing said case. The blank comprises a band (2) of panels (15, 16, 17, 18) connected together in pairs by parallel fold lines (24, 25, 26, 27). The band (2) comprises a precut transverse line (20) making it possible to divide the blank into two half-blanks (21, 22), said transverse line determining on either side and for each parallel fold line (24, 25, 26, 27) two separate portions of fold line (24?, 24?; 25?, 25?; 26?, 26?; 27?, 27?) offset relative to one another in order to make it possible to at least partly compensate for the thicknesses of cardboard when the second half-blank is wrapped over the first half-blank around a mandrel.