Abstract: The method and the device serves for the production of defined stacks of folded or unfolded sheets. The individually supplied sheets are placed on edge onto a horizontal table whereby the separation of the individual stacks is achieved by a separating support that is advanced parallel to the table at the stack forming velocity. In order to be able to separate and individualize product stacks of differently sized sheets without the need for structural adaptation of the device, the formation of a first separating plane defining the beginning of the stack as well as the formation of a second separating plane defining the end of the stack is achieved by a separating support that is insertable between the sheets in a direction transverse to the longitudinal extension of the table. Further supports are completely insertable into the thus formed separating planes.