Abstract: The invention provides a computer system utilizing bi-directional communication between a computing device and a printing machine, for transmitting data representing real-time supply roll parameters to an application program on the computing device. Supply roll parameters are stored on a memory circuit component that is connected to a supply roll. The computing device polls the printing machine for the supply roll parameters. The printing machine transmits the supply roll parameters to the computing device and the computing device formats the parameters into a display, proportionately matching the dimensions and color of the actual supply roll. A user can then create and/or edit output files for the specific supply roll loaded in the printing machine, viewing the output exactly as it will be printed.

Abstract: A tape is controlled in a printing machine by advancing a length of tape through a light pathway. Transmittance of the light through the tape is measured and values are stored associated with transmittances through the tape. The tape is advanced to a start position where measured transmittance of the tape at the start position corresponds with a stored value of a measured transmittance.