Printing issues with 4x6 labels when using a Datamax MK III label printer with SendPro Online or PitneyShip

Learn how to resolve an issue with Datamax MK III label printer not printing 4x6 inch shipping labels when using SendPro Online or PitneyShip.
Products affected: SendPro® Online, PitneyShip™


The Datamax MK III printer will not print labels.


There may be an issue with the Datamax MK III printer or an issue in the Windows operating system.


Solution 1: Ensure that the printer driver is installed

See Installing the Datamax Mark III printer.

Solution 2: Ensure that the roll in the Datamax MK III printer is correctly installed

With the roll sitting between the two green pressure brackets, make sure of the following:

  • The roll feeds from the top
  • The labels are facing up and the glossy backing paper is facing down
  • The roll feeds under the two green guides
  • The leading end of the roll rests on the black and green roller inside the printer

If the leading end of the roll sticks out of the printer when the cover is closed, press start/pause on the cover of the printer once. This causes the leading end of the roll to position itself at the end of the container.

Datamax Mark III printer rollers, guides, and brackets

Solution 3: Run a test print

  1. Select the Windows Start > Devices and Printers.
  2. Right-click the Datamax-ONeil Mark III printer and select Printer Properties.
  3. Select the General tab.
  4. Select Print Test Page.

Note: These steps work for most inkjet or laser printers.

  • If you cannot run a test print from the printer, then the issue is with the printer, not with SendPro Online or PitneyShip. Contact your local IT department or the printer manufacturer.
  • If the test print works from the printer, but you cannot print from SendPro Online or PitneyShip, then the issue is with SendPro Online or PitneyShip.

If print quality is poor:

  1. Click Windows Start.
  2. Open Control Panel.
  3. Right-click on the Datamax MK III printer and choose Printer Preferences.
  4. Click the Graphics tab.
  5. Set Dithering to None.
  6. Click OK.

If you need further assistance, please contact us.

UPDATED: May 09, 2022

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