A printer , comprising: a plurality of sensors positioned within a print path before a printhead location , said sensors generating a signal indicative of a highest point of incoming media (100; 200; 300) relative to a reference surface of the printer ; a control system in communication with said sensors configured to, in response to receiving said sensors signals, determine when the height of the highest point of the incoming media (100; 200; 300) relative to the reference surface of the printer poses a collision or damage risk to the printer ; said control system being configured to generate a signal that stops operation of the printer when the height of the highest point of said incoming media (100; 200; 300) relative to the reference surface of the printer poses a collision or damage risk to the printer ; characterised in that the control system is configured as follows: when said control system , in response to receiving said sensors signals, determines that the height of the incoming media (100; 200; 300) relative to the reference surface of the printer does not pose a collision or damage risk to the printer and said control system determines that the height of the incoming media (100; 200; 300) relative to the reference surface of the printer does not allow printing of the media (100; 200; 300), said control system generates a signal that rejects the media (100; 200; 300) after the media (100; 200; 300) is passed through the printer without being printed and without stopping or slowing down printer operation; and when said control system , in response to receiving said sensors signals, determines that the height of the incoming media (100; 200; 300) allows printing of the media (100; 200; 300), said control system generates a signal that adjusts printhead height relative to an upper media surface distance to prevent interference with the media (100; 200; 300) while allowing the printheads to print. a plurality of sensors positioned within a print path before a printhead location , said sensors generating a signal indicative of a highest point of incoming media (100; 200; 300) relative to a reference surface of the printer ; a control system in communication with said sensors configured to, in response to receiving said sensors signals, determine when the height of the highest point of the incoming media (100; 200; 300) relative to the reference surface of the printer poses a collision or damage risk to the printer ; said control system being configured to generate a signal that stops operation of the printer when the height of the highest point of said incoming media (100; 200; 300) relative to the reference surface of the printer poses a collision or damage risk to the printer ; characterised in that the control system is configured as follows: when said control system , in response to receiving said sensors signals, determines that the height of the incoming media (100; 200; 300) relative to the reference surface of the printer does not pose a collision or damage risk to the printer and said control system determines that the height of the incoming media (100; 200; 300) relative to the reference surface of the printer does not allow printing of the media (100; 200; 300), said control system generates a signal that rejects the media (100; 200; 300) after the media (100; 200; 300) is passed through the printer without being printed and without stopping or slowing down printer operation; and when said control system , in response to receiving said sensors signals, determines that the height of the incoming media (100; 200; 300) allows printing of the media (100; 200; 300), said control system generates a signal that adjusts printhead height relative to an upper media surface distance to prevent interference with the media (100; 200; 300) while allowing the printheads to print. <EOS>