Configuring Firefox to Print to Receipt Printer

• Open File > Page Setup
• Make all the headers and footers blank
• Set the margins to 0 (zero)
• In the address bar of Firefox, type about:config
• Search for print.always_print_silent and double click it
• Change it from false to true
  
  • This lets you skip the Print pop up box that comes up, as well as skipping the step where you have to click OK, automatically printing the right sized slip.
• If print.always_print_silent does not come up
  
  • Right click on a blank area of the preference window
  • Select new > Boolean
  • Enter "print.always_print_silent" as the name (without quotes)
  • Click OK
  • Select true for the value
• You may also want to check what is listed for print.print_printer
  
  • You may have to choose Generic/Text Only (or whatever your receipt printer might be named)
    
    
    
    To disable printing options from Firefox's Print Preview window:
    In the address bar type "about:config" and press Enter.
    In the Filter field search for "print.whileInPrintPreview".
    Double-click on this entry to switch its value to "False".