Method for inserting at least one insert in multi-sheet printed products consisting of printed sheets and/or individual sheets, each having a back, that are transported by means of carriers pushing in a conveying direction with backs aligned parallel to the conveying direction in a conveying device aligned according to two reference edges (7, 8) and with backs facing down, characterised in that - in a format preparing step at least two printed sheets and/or individual sheets are each produced with a format in which at least one of the printed sheets or at least one of the individual sheets has a format that is different from the other printed sheets and/or individual sheets and - the printed sheets and/or individual sheets are put together to form multi-sheet printed products in which at least one separation point (T 1... T 8) is formed through arranging at least two printed sheets or individual sheets of different formats or a printed sheet and individual sheets of different formats directly adjacent to each other, in which the at least one printed sheet and/or at least one individual sheet projects from the multi-sheet printed product, - in a first step multi-sheet printed products having at least one predetermined separation point (T1... T8) between two adjacent printed sheets and/or individual sheets are supplied, in which at least one printed sheet and/or at least one individual sheet projects from the multi-sheet printed product, - in a second step the multi-sheet printed products are opened at the at least one separation point (T 1... T 8), in which the printed products that contain the at least one printed sheet and/or the at least one individual sheet with a back length (R 1... R 5) that is different from the other printed sheets and/or individual sheets are opened on a front edge by means of opener elements inserted sideways in the separation point (T 1... T 4), in which the opener elements are driven at a first speed and the carriers at a second speed, in which both speeds are at least approximately the same in the conveying direction, - in a third step the at least one separation point (T 1... T 8) is extended in the multi-sheet printed products and - in a fourth step at least one insert is inserted in the extended separation point (T 1... T 8). - in a format preparing step at least two printed sheets and/or individual sheets are each produced with a format in which at least one of the printed sheets or at least one of the individual sheets has a format that is different from the other printed sheets and/or individual sheets and - the printed sheets and/or individual sheets are put together to form multi-sheet printed products in which at least one separation point (T 1... T 8) is formed through arranging at least two printed sheets or individual sheets of different formats or a printed sheet and individual sheets of different formats directly adjacent to each other, in which the at least one printed sheet and/or at least one individual sheet projects from the multi-sheet printed product, - in a first step multi-sheet printed products having at least one predetermined separation point (T1... T8) between two adjacent printed sheets and/or individual sheets are supplied, in which at least one printed sheet and/or at least one individual sheet projects from the multi-sheet printed product, - in a second step the multi-sheet printed products are opened at the at least one separation point (T 1... T 8), in which the printed products that contain the at least one printed sheet and/or the at least one individual sheet with a back length (R 1... R 5) that is different from the other printed sheets and/or individual sheets are opened on a front edge by means of opener elements inserted sideways in the separation point (T 1... T 4), in which the opener elements are driven at a first speed and the carriers at a second speed, in which both speeds are at least approximately the same in the conveying direction, - in a third step the at least one separation point (T 1... T 8) is extended in the multi-sheet printed products and - in a fourth step at least one insert is inserted in the extended separation point (T 1... T 8).