PURPOSE: To surely make a box by means of a packaging machine for corrugated fiberboard even from a paper board.

CONSTITUTION: A paper board is used as a blank B, which is formed into a box by a sack sticking method, and in the blank B, each of two folding rules, which serve as folding lines at least at the time of sack sticking, is constituted of a folding rule provided with one or more crushed rules α midway in a main rule β. Since when the blank B is sack stuck, the blank is not fully folded at the crushed rule and a swelling remains and hence a repulsive force is produced so that a box can be easily raised, and hence even if a paper board, which is inexpensive and on which a fine printing can be applied, is used, boxes can be sufficiently made using a prior art packaging machine for corrugated fiberboard. And in a blank which is formed into a box by a wraparound method, similar crushed rules are provided in four folding rules, which serve as ridge lines of a body part, whereby the blank can be surely folded at the folding rules.