Abstract: The process is for cutting rough mother sheets TM issuing from a rolling mill into daughter sheets of predetermined dimensions. In the course of this process, there is determined the inscribability of each mother sheet so as to establish a marking plan permitting an optimum utilization of the sheet. Each mother sheet is passed through devices 5, 6 for cutting the sheet to dimensions and cutting the daughter sheets. The determination of the inscribability comprises projecting onto the mother sheet TM a network of crossing luminous lines t.sub.1, t.sub.2, t.sub.3 -a to t.sub.3 -g, selectively shifting each of the luminous lines while maintaining it parallel to itself so as to define on the mother sheet a batch of daughter sheets to be obtained, determining the coordinates of the luminous lines relative to a reference system pertaining to the mother sheet, and cutting the mother sheet in accordance with the obtained coordinates.