When the printer is printing, there may be a printer icon in the system tray unless the document is very small or the printer has a built-in page buffer. It was there, but Windows considered the document finished, and the icon disappeared as the print spooler completed delivering all data to the printer.
Stop printer in the middle of a project!!!!
If it appears while printing, right-click it and select "Cancel all Documents."
If the printer dialog box shows up for the printer, click "Printer" and the select "Cancel all Documents"
If the printer has a page buffer, there may be yet another icon in the tray specifically put there by the printer driver/utility and it will have a cancel print jobs feature.