Cleaning the printhead after each roll of labels will help to extend the life of the printhead. A clean printhead will also provide optimal print quality.
Procedure:

After allowing the print head to cool for approximately one minute, use 99.7% Isopropyl alcohol on a cotton swab to clean the print elements from end to end (the print elements are located in the dark line on the print head).
NOTE: You do not have to turn off the printer to do this.

If print quality has not improved after performing this procedure, try cleaning the print head with Save-a-Print head cleaning film Zebra P/N 46902. This specially coated material removes contamination buildup without damaging the print head. Read More>>
Call your authorized reseller for more information.
Cleaning Pens and Kit information Read More>>
This video demonstrates cleaning the printhead using the Cleaning Pen.