Reason 1:  The source file may not have been created with the ideal quality. 

Solution: Print the sample label to test if your printer is working well. 

If the sample label is good, check the file quality.

 

Reason 2:  High print speed or density. 

Solution: Try reducing your print speed (try 3 in/sec) and density (try 3 as well) to see if you get a better result.

For Mac

Select "Printer Features" in "Preview" 

Set the print density in "Darkness" 

Set the print speed in "Print Speed" 

 

For Windows

Open “Devices and Printers” -> right click on “Label Printer” -> choose “Printer Preferences” -> click “Advanced”

Set the print speed in "Speed"

Set the print density in "Density"