Abstract: A printing process for a substantially light-insensitive thermographic monosheet material having two edges parallel to one another and >12 cm apart (non-label) for obtaining a desired optical density and a desired colour tone comprising: selecting a thermographic monosheet material, the selected thermographic monosheet material being a black and white thermographic monosheet material having a support and a thermosensitive element; supplying image data to a processing unit of a thermal printer including a printhead having energizable heating elements arranged in a column C; converting the image data which are not zero into at least one activation pulse per pixel to be printed; energising the heating elements printing-line by printing-line adjacent to the selected substantially light-insensitive thermographic monosheet material thereby producing an image; transporting the imaging material past and adjacent to the printhead in a transport direction with a transport system; forming an image dot with a h