Magazines, pamphlets or books, coming from upstream machinery are conveyed on an automatic line to the wrapping or palletizing machine. Before arriving there, they are fed into a book collation machine to be stacked. Once, the bundle leaves the turntable of the stacker the sudden speed of movement of the machine may cause the unstable packs to shift or fall over. Compensating stackers are equipped with electrostatic charging bars at the top and from both sides, using different opposite polarities, stabilising the bundle of magazine into “brick-like” stacks to secure further transport.