A controller for a printer capable of processing multiple images simultaneously, comprising: a process monitor configured to determine which images of a plurality of images are currently being processed simultaneously by the printer; and a display configured to indicate to a user, based on the determining by the process monitor, which images of the plurality of images are currently being processed simultaneously by the printer, wherein the controller further comprises at least one interface configured to receive the plurality of images and for receiving property data indicating properties of the printer and/or of a medium supplied to the printer for printing thereon; and a nesting logic configured to create and/or update printing instructions for the printer based on properties of the received images and/or based on the property data, the printing instructions indicating to the printer in which arrangement the printer is to print the plurality of images onto the medium; wherein the process monitor is configured to determine which images of the plurality of images are currently being printed simultaneously using the printing instructions, and wherein the controller further comprises a user interface configured to receive an abortion command from a user, the abortion command indicating that printing of at least one of the plurality of images should be aborted, wherein printing is applying a marking material onto the medium; wherein the nesting logic is configured to update the printing instructions for the printer to abort the printing of the at least one of the plurality of images indicated by the abortion command, while printing the at least one of the plurality of images, and, wherein the nesting logic is configured such that, when at least one of the images indicated by the abortion command is one of the images being currently processed as determined by the process monitor, the printing instructions for the printer are updated such that, of the images being currently printed, only the images indicated by the abortion command are aborted, whereas images not indicated by the abortion command continue to be printed. a process monitor configured to determine which images of a plurality of images are currently being processed simultaneously by the printer; and a display configured to indicate to a user, based on the determining by the process monitor, which images of the plurality of images are currently being processed simultaneously by the printer, wherein the controller further comprises at least one interface configured to receive the plurality of images and for receiving property data indicating properties of the printer and/or of a medium supplied to the printer for printing thereon; and receiving property data indicating properties of the printer and/or of a medium supplied to the printer for printing thereon; and a nesting logic configured to create and/or update printing instructions for the printer based on properties of the received images and/or based on the property data, the printing instructions indicating to the printer in which arrangement the printer is to print the plurality of images onto the medium; wherein the process monitor is configured to determine which images of the plurality of images are currently being printed simultaneously using the printing instructions, and wherein the controller further comprises a user interface configured to receive an abortion command from a user, the abortion command indicating that printing of at least one of the plurality of images should be aborted, wherein printing is applying a marking material onto the medium; wherein the nesting logic is configured to update the printing instructions for the printer to abort the printing of the at least one of the plurality of images indicated by the abortion command, while printing the at least one of the plurality of images, and, wherein the nesting logic is configured such that, when at least one of the images indicated by the abortion command is one of the images being currently processed as determined by the process monitor, the printing instructions for the printer are updated such that, of the images being currently printed, only the images indicated by the abortion command are aborted, whereas images not indicated by the abortion command continue to be printed.