The X-Rite model 390 and 391 densitometers can connect to certain parallel printers only. All other printers will not work with the 390/391. For a complete list of compatible printers, scroll down to the "Interfacing with Third Party Applications" list on the Support page for the 390 or 391 at the following link: http://www.xrite.com/product_overview.aspx?ID=99&Action=Support
The compatible printers are no longer manufactured and will be difficult to obtain at this time.
Many users are choosing to purchase X-Read QC software (p/n: 1261) from X-Rite and then connect the 390/391 to a computer that will in turn print to whatever printer is connected to the computer. To purchase X-Read software, contact X-Rite Customer Service.
If the customer wishes to purchase the printer cable for a compatible parallel printer, the part number is: SE130-SERPAR