Setting Up a Zebra Label Printer on a Mac (ZD421 and Similar)

You can print QrX shipping labels on a Zebra label printer, such as the Zebra ZD421, from a Mac, including Macs with Apple Silicon (M1, M2, M3, M4 and later). Zebra does not offer a separate Mac driver, and you do not need a paid third-party driver: macOS already includes a Zebra ZPL Label Printer driver. You add the printer on the Mac first, then connect it to QrX through PrintNode.

Step 1: Add the Printer on Your Mac

Connect the Zebra printer with a USB cable, or connect it to the same network as your Mac, and switch it on.
Open System Settings > Printers & Scanners and click Add Printer, Scanner or Fax.
USB: select the Zebra printer in the list (a ZD421 shows as for example ZTC ZD421-203dpi ZPL).
Network: open the IP tab, enter the printer's IP address and choose protocol HP Jetdirect - Socket.
At Use, choose Select Software, search for Zebra and pick Zebra ZPL Label Printer. Do not use AirPrint, Generic PostScript or Generic PCL: those print blank or garbled labels.
Click Add.

Step 2: Set the Label Size to 4 x 6

The macOS Zebra driver starts with a 4 x 5 inch label size. Shipping labels are 4 x 6 inch, so change the default once in the Terminal app.

Open Terminal and run lpstat -p. Note the name of your Zebra printer, for example Zebra_ZD421.
Run sudo lpadmin -p Zebra_ZD421 -o PageSize-default=w288h432 with your own printer name. Enter your Mac login password when asked (nothing appears while you type). w288h432 is the driver's name for 4 x 6 inch.
Only for the 300 dpi model, also run sudo lpadmin -p Zebra_ZD421 -o Resolution-default=300dpi. A standard ZD421 prints at 203dpi, which is already the default.
Print a label from QrX after Step 3 to check that the full 4 x 6 label prints.

Step 3: Connect the Printer to QrX with PrintNode

Install the PrintNode client for Mac and sign in with your PrintNode account. On a Mac with Apple Silicon, macOS may ask to install Rosetta the first time; allow it.
Check that the Zebra printer appears in the PrintNode client.
In PortalX go to Settings > Preferences > Printing and click Load Printers.
Choose the Zebra as Default Label Printer and set the Default Label Paper Format to PDF 4x6.
Print a label from the Transactions list to confirm.

Use PDF 4x6 on a Mac. The Zebra driver converts the PDF for the printer. The format ZPL 4x6 (Zebra) sends raw printer code and only works with a raw print queue. To create one, run lpstat -v in Terminal to see your printer's address, then run lpadmin -p Zebra_Raw -E -v "<printer address>" -m raw and choose Zebra_Raw in PortalX. Keep the normal queue for everything else.

Common Problems

Labels are cut off, or a blank label comes out after each label: the label size is not 4 x 6. Repeat Step 2. If the printer still skips labels, calibrate it: on a ZD421, hold Pause and Cancel together for two seconds.
The printer prints lines of code instead of a label: the paper format is ZPL 4x6 on a normal queue. Switch to PDF 4x6, or use a raw queue as described above.
The printer does not appear in PortalX: check that the PrintNode client is running and shows the printer, then click Load Printers again.
Print is too light: raise the darkness a few steps at a time, for example sudo lpadmin -p Zebra_ZD421 -o Darkness-default=20 (values 1 to 30).
The label size did not change: check the printer name with lpstat -p and run the command from Step 2 again with exactly that name.

When to Contact Our Support Team

Contact QrX when the printer prints a correct test page from the Mac and shows online in PrintNode, but jobs from QrX keep failing in the Print Queue, or when a carrier label prints in the wrong size although the label size is set to 4 x 6.