Abstract: A material modifying device for use in modifying a sheet material. The material modifying device comprising: an instrument for modifying the sheet material, a carriage, a sheet material holder for holding the sheet material on said surface; a controller for receiving modification instructions for how the instrument is to modify the sheet material, and at least one sensor configured for sensing the position of the sheet material, the sensor generating at least one position signal, the position signal received by the controller, wherein considering the position signal, the controller executes the modification instructions and moves the carriage relative to the sheet material holder and the sheet material holder relative to the carriage so that the instrument modifies the sheet material according to the modification instructions.

Abstract: An instrument holder for holding an instrument having a body and a tip in a plotter. The instrument holder comprising a body portion, a tensioner portion for centering the instrument within the instrument holder and for gripping the instrument, and a cap portion for allowing a user thereof to adjust the grip provided by the tensioner portion on the instrument.