Abstract: A box having a cover with a plurality of windows and at least a majority of the windows being elongated and oriented in generally spaced relationship with respect to each other. Each window is defined at least in part by a pair of spaced window defining sides. A first or leading series of such window defining sides is disposed in non-parallel relationship with each of a second or trailing series of window defining sides. This serves to facilitate manufacture of boxes from blanks that are readily movable over each other without undesirable edge-to-edge continuous contact which inhibits relative sliding movement during manufacture. The non-parallel window defining sides may be inwardly concave or have each window defined in part by a pair of straight window defining sides which diverge. An associated method for establishing container blanks of this type is disclosed.